USDA Bovine Spongiform Encephalopathy BSE, Scrapie, CWD, Testing and Surveillance 2022 A Review of History
Greetings, i lost my Mom to the Heidenhain Variant of Creutzfeldt Jakob Disease hvCJD way back on December 14, 1997. At the same time, we were watch Oprah Winfrey defend herself against the Cattle Industry in Texas about that Mad Cow Hamburger and those staggering cows she showed on her T.V. I said right then we had a problem here in the USA, and nobody was taking it seriously.
Since the, I have followed the science daily on TSE Prion, and every year around this time, i like to put together an annual report of sorts for BSE, Scrapie, CWD, now CPD i.e Camel Prion Disease, and the different Human TSE Prion strains. sometimes i may report on them individually, and sometimes just one report that includes all of it.
I sit here today in 2022 and say the same thing i said back from 1998 and forward, and would kindly like to show you. In fact, the Texas Mad Cow (the second one, the first one was sent off to be rendered without any testing at all, but this is the second one i speak of now), this cow Texas tried to cover up with BSE testing that was the least likely to find BSE, and in fact, i was so concerned, i wrote the OIG Office of Inspector General, and i also sent of letters to a bunch of scientist that i was concerned this cow that was negative, was in fact positive. After a year of mad cow wrangling with Scientist and the OIG, that negative mad cow was CONFIRMED AS POSITIVE. I will review Past and Present BSE testing, surveillance, the infamous 'Enhanced BSE Surveillance'' and the Harvard Assessment ONE and TWO, and a failed attempt to combat this deadly zoonotic disease, or was it a successful attempt at failing to find BSE in the USA?
I believe, imo, and through decades of following this daily, that the USDA/APHIS BSE Testing formula was intentionally set up to never detect BSE TSE Mad Cow disease, and this includes Scrapie TSE in Sheep and Goat.
so, let's review the facts.
FIRST, let's review what the EU is doing today, in terms of testing figures, surveillance, and detection in 2021...
The European Union summary report on surveillance for the presence of transmissible spongiform encephalopathies (TSE) in 2021
Published:
30 November 2022
Approved: 3 November 2022
Metadata
EFSA Journal 2022;20(11):7655
Keywords: TSE, BSE, CWD, scrapie, classical, atypical, surveillance
On request from: European Commission Question Number: EFSA‐Q‐2021‐00765
Contact: zoonoses@efsa.europa.eu
Abstract
This report presents the results of surveillance on transmissible spongiform encephalopathies (TSE) in cattle, sheep, goats, cervids and other species, and genotyping in sheep and goats, carried out in 2021 by 27 Member States (MS, EU27), the United Kingdom (in respect of Northern Ireland) (XI), and eight other non‐EU reporting countries: Bosnia and Herzegovina, Iceland, Montenegro, North Macedonia, Norway, Serbia, Switzerland and Turkey.
In total, 1,021,252 cattle were tested by EU27 and XI (−9%, compared with 2020 when data from the United Kingdom were not restricted to Northern Ireland), and 66,121 cattle by eight non‐EU reporting countries,
with two cases of H‐BSE in France and Spain, and four L‐BSE in France (2), Germany and Spain.
In total, 311,174 sheep and 118,457 goats were tested in the EU27 and XI (−6.4% and −1.8%, respectively, compared to 2020 when data from the whole United Kingdom were considered).
In sheep, 551 cases of scrapie were reported by 17 MS and XI: 448 classical scrapie (CS) by six MS [80 index cases (IC) with genotypes of susceptible groups in 97% of the cases], 103 atypical scrapie (AS) (96 IC) by 13 MS and XI.
In the other non‐EU reporting countries, 27,594 sheep were tested with 55 CS and 1 AS in Iceland and 8 AS in Norway.
Ovine random genotyping was reported by nine MS and genotypes of susceptible groups accounted for 7.9%.
In goats, 224 cases of scrapie were reported by six EU MS: 219 CS (30 IC) by six MS, and five AS (5 IC) by three MS.
In total, 5,854 cervids were tested for chronic wasting disease by eight MS; all resulted negative. Norway tested 21,670 cervids with two moose and one red deer positive. In total, 149 animals from four other species tested negative in Finland and Turkey.
© European Food Safety Authority
see full text;
SECOND, let's review the USDA/APHIS et al BSE, Scrapie, and CWD testing, past and present...
USDA BSE Surveillance Information Center
Introduction USDA conducts surveillance for Bovine spongiform encephalopathy (BSE), referred to as "mad cow disease", in cattle to determine if, and at what level, the disease is present in the U.S. cattle population. Our surveillance program allows us to assess any change in the BSE disease status of U.S. cattle, and identify any rise in BSE prevalence in this country. Identifying any changes in the prevalence of disease allows us to match our preventive measures - feed ban for animal health, and specified risk material removal for public health - to the level of disease in U.S. cattle.
It is the longstanding system of interlocking safeguards, including the removal of specified risk materials - or the parts of an animal that would contain BSE - at slaughter and the FDA's ruminant-to-ruminant feed ban that protect public and animal health from BSE.
Why did USDA decrease the number of samples per year in 2006? After the first confirmation of BSE in an animal in Washington State in December 2003, USDA evaluated its BSE surveillance efforts in light of that finding. We determined that we needed to immediately conduct a major surveillance effort to help determine the prevalence of BSE in the United States. Our goal over a 12-18 month period was to obtain as many samples as possible from the segments of the cattle population where we were most likely to find BSE if it was present. This population of cattle was exhibiting some signs of disease. We conducted this enhanced surveillance effort from June 2004 - August 2006. In that time, we collected a total of 787,711 samples and estimated the prevalence of BSE in the United States to be between 4-7 infected animals in a population of 42 million adult cattle. We consequently modified our surveillance efforts based on this prevalence estimate to a level we can monitor for any potential changes, should they occur. Our statistical analysis indicated that collecting approximately 40,000 samples per year from the targeted cattle population would enable us to conduct this monitoring.
Why is USDA "only" testing 25,000 samples a year? USDA's surveillance strategy is to focus on the targeted populations where we are most likely to find disease if it is present. This is the most effective way to meet both OIE and our domestic surveillance standards. After completing our enhanced surveillance in 2006 and confirming that our BSE prevalence was very low, an evaluation of the program showed that reducing the number of samples collected to 40,000 samples per year from these targeted, high risk populations would allow us to continue to exceed these standards. In fact, the sampling was ten times greater than OIE standards. A subsequent evaluation of the program in 2016 using data collected over the past 10 years showed that the surveillance standards could still be met with a further reduction in the number of samples collected by renderers and 3D/4D establishments which have a very low OIE point value because the medical history of these animals is usually unknown. Therefore, in 2016, the number of samples to be tested was reduced to 25,000 where it remains today.
How can USDA find every case of BSE in the United States when you are only testing 25,000 animals? The goal of our BSE surveillance program, even under the enhanced program, has never been to detect every case of BSE. Our goal is determine whether the disease exists at very low levels in the U.S. cattle population, and we do this by testing those animals most likely to have BSE. It is the longstanding system of interlocking safeguards, including the removal of specified risk materials - or the parts of an animal that would contain BSE - at slaughter and the FDA's ruminant-to- ruminant feed ban that protect public and animal health from BSE.
Why didn’t USDA continue to test animals at the enhanced surveillance level? USDA's 2004-2006 enhanced surveillance program was initiated in response to the first detection of BSE in the United States and was designed to detect the overall prevalence of the disease in this country. This required a very intensive effort and it allowed us to estimate extremely low prevalence levels of disease. Once that prevalence level was determined, USDA modified its testing levels to monitor any changes in the level of disease. Our current testing of approximately 25,000 targeted animals a year allows USDA to detect BSE at the very low level of less than 1 case per million adult cattle, assess any change in the BSE status of U.S. cattle, and identify any rise in BSE prevalence in this country.
Is USDA's surveillance program a food safety or public health measure? The primary, and most effective, food safety or public health measure is the removal of specified risk materials (SRMs) - or the parts of an animal that would contain BSE - from every animal at slaughter. USDA's BSE surveillance program is not a food safety measure; it is an animal health monitoring measure. However, it does support existing public health and food safety measures. By allowing us to monitor the level of disease in the US cattle population, we can help determine the appropriate level of public health and animal health measures required, and whether they should be increased or decreased.
Why doesn't USDA test every animal at slaughter? There is currently no test to detect the disease in a live animal. BSE is confirmed by taking samples from the brain of an animal and testing to see if the infectious agent - the abnormal form of the prion protein - is present. The earliest point at which current tests can accurately detect BSE is 2 to 3 months before the animal begins to show symptoms, and the time between initial infection and the appearance of symptoms is about 5 years. Therefore, there is a long period of time during which current tests would not be able to detect the disease in an infected animal.
Since most cattle are slaughtered in the United States at a young age, they are in that period where tests would not be able to detect the disease if present. Testing all slaughter cattle for BSE could produce an exceedingly high rate of false negative test results and offer misleading assurances of the presence or absence of disease.
Simply put, the most effective way to detect BSE is not to test all animals, which could lead to false security, but to test those animals most likely to have the disease, which is the basis of USDA's current program.
What animals are USDA testing in the surveillance program? These are random samples at slaughter, aren't they? No. USDA's BSE surveillance program is specifically targeted to the population most likely to have the disease, if it is present. This population is NOT clinically healthy animals that would be presented for slaughter. Rather, it includes animals that have some type of abnormality, such as central nervous system signs; non-ambulatory, or a "downer"; emaciated; or died for unknown reasons. Because these animals would not pass the required ante-mortem inspection requirements at slaughter for human consumption, we collect the majority of our samples at facilities other than slaughter facilities - at rendering or salvage facilities, on-farm, at veterinary clinics or veterinary diagnostic laboratories. With this targeted approach, we can monitor the presence of disease in the US cattle population in a much more efficient and meaningful way. The key to surveillance is to look where the disease is going to occur.
Key Points: BSE Ongoing Surveillance Plan Note: This Fact Sheet is based on the USDA Animal and Plant Health Inspection Service (APHIS) Bovine Spongiform Encephalopathy (BSE) Ongoing Surveillance Plan, July 20, 2006. To learn more, read the complete BSE Ongoing Surveillance Plan (PDF, 187 KB).
KEY POINTS In addition to a stringent feed ban imposed by the Food and Drug Administration in 1997 as well as the removal of all specified risk material which could harbor BSE, USDA has a strong surveillance program in place to detect signs of BSE in cattle in the United States. In fact, we test for BSE at levels greater than World Animal Health Organization standards. The program samples approximately 25,000 animals each year and targets cattle populations where the disease is most likely to be found. The targeted population for ongoing surveillance focuses on cattle exhibiting signs of central nervous disorders or any other signs that may be associated with BSE, including emaciation or injury, and dead cattle, as well as non-ambulatory animals. Samples from the targeted population are taken at farms, veterinary diagnostic laboratories, public health laboratories, slaughter facilities, veterinary clinics, and livestock markets.
USDA's National Veterinary Services Laboratories (NVSL) in Ames, IA, along with contracted veterinary diagnostic laboratories, use rapid screening tests as the initial screening method on all samples. Any inconclusive samples undergo further testing and analysis at NVSL.
NOT A FOOD SAFETY TEST BSE tests are not conducted on cuts of meat, but involve taking samples from the brain of a dead animal to see if the infectious agent is present. We know that the earliest point at which current tests can accurately detect BSE is 2-to-3 months before the animal begins to show symptoms. The time between initial infection and the appearance of symptoms is about 5 years. Since most cattle that go to slaughter in the United States are both young and clinically normal, testing all slaughter cattle for BSE might offer misleading assurances of safety to the public.
The BSE surveillance program is not for the purposes of determining food safety. Rather, it is an animal health surveillance program. USDA's BSE surveillance program allows USDA to detect the disease if it exists at very low levels in the U.S. cattle population and provides assurances to consumers and our international trading partners that the interlocking system of safeguards in place to prevent BSE are working.
The safety of the U.S. food supply from BSE is assured by the removal of specified risk materials - those tissues known to be infective in an affected animal - from all human food. These requirements have been in place since 2004.
ONGOING BSE SURVEILLANCE PROGRAM SUMMARY USDA's BSE surveillance program samples approximately 25,000 animals each year and targets cattle populations where the disease is most likely to be found. The statistically valid surveillance level of 25,000 is consistent with science-based internationally accepted standards. This level allows USDA to detect BSE at the very low level of less than 1 case per million adult cattle, assess any change in the BSE status of U.S. cattle, and identify any rise in BSE prevalence in this country.
The targeted population for ongoing surveillance focuses on cattle exhibiting signs of central nervous disorders or any other signs that may be associated with BSE, including emaciation or injury, and dead cattle, as well as nonambulatory animals. Samples from the targeted population are taken at farms, veterinary diagnostic laboratories, public health laboratories, slaughter facilities, veterinary clinics, and livestock markets.
USDA's National Veterinary Services Laboratories (NVSL) in Ames, IA, along with contracted veterinary diagnostic laboratories, will continue to use rapid screening tests as the initial screening method on all samples. Any inconclusive samples will be sent to NVSL for further testing and analysis. USDA's surveillance program uses OIE's weighted surveillance points system, which was adopted in May 2005 and reflects international scientific consensus that the best BSE surveillance programs focus on obtaining quality samples from targeted subpopulations rather than looking at the entire adult cattle population.
The number of points a sample receives correlates directly to an animal's clinical presentation at the time of sampling. The highest point values are assigned to those samples from animals with classic clinical signs of the disease. The lowest point values correspond to clinically normal animals tested at routine slaughter.
The goal of this weighted approach is to ensure that countries sample those cattle populations where the disease is most likely to be found. This system is not different from USDA's previous BSE surveillance approach, it is simply a different method for evaluating surveillance programs. Both approaches target those cattle populations where BSE is most likely to be found. The OIE is simply assigning point values to different categories of animals.
USDA has been targeting these subpopulations since BSE surveillance was initiated in 1990, and will continue to do so under the OIE weighted approach. Under the OIE guidelines, points compiled over a period of 7 consecutive years are used as evidence of adequate surveillance. At the current ongoing level of surveillance, the United States will far exceed OIE guidelines under the point system.
MY BULLSHIT METER PEGGED OUT ON THE ABOVE BSe by USDA et al!
COMPARING the EU, to the USA, on BSE Surveillance and Testing, you can see for yourself why the EU is finding more, because they are testing more, compared to USA.
''USDA's 2004-2006 enhanced surveillance program was initiated in response to the first detection of BSE in the United States and was designed to detect the overall prevalence of the disease in this country.''
I would kindly like to remind everyone of this very important document;
BSE research project final report 2005 to 2008 SE1796 SID5
I was very concerned of the BSE testing and even discussed this with Bio-Rad et al;
Audit Report
Animal and Plant Health Inspection Service
Bovine Spongiform Encephalopathy (BSE) Surveillance Program – Phase II
and
Food Safety and Inspection Service
Controls Over BSE Sampling, Specified Risk Materials, and Advanced Meat Recovery Products - Phase III
Report No. 50601-10-KC January 2006
Finding 2 Inherent Challenges in Identifying and Testing High-Risk Cattle
Still Remain Our prior report identified a number of inherent problems in
identifying and testing high-risk cattle.
snip...
BIO-RAD
> > -------- Original Message --------
> > Subject: USA BIO-RADs INCONCLUSIVEs
> > Date: Fri, 17 Dec 2004 15:37:28 -0600
> > From: "Terry S. Singeltary Sr."
> > To:
> >
> >
> >
> > Hello xxxx and Bio-Rad,
> >
> > Happy Holidays!
> >
> > I wish to ask a question about Bio-Rad and USDA BSE/TSE testing
> > and there inconclusive. IS the Bio-Rad test for BSE/TSE that
complicated,
> > or is there most likely some human error we are seeing here?
> >
> > HOW can Japan have 2 positive cows with
> > No clinical signs WB+, IHC-, HP- ,
> > BUT in the USA, these cows are considered 'negative'?
> >
> > IS there more politics working here than science in the USA?
> >
> > What am I missing?
> >
> >
> >
> > -------- Original Message --------
> > Subject: Re: USDA: More mad cow testing will demonstrate beef's safety
> > Date: Fri, 17 Dec 2004 09:26:19 -0600
> > From: "Terry S. Singeltary Sr."
> > snip...end
> >
> >
> > Experts doubt USDA's mad cow results
>
>
>
> snip...END
>
> WELL, someone did call me from Bio-Rad about this,
> however it was not xxxxxx xxxxx.
> but i had to just about take a blood oath not to reveal
> there name. IN fact they did not want me to even mention
> this, but i feel it is much much to important. I have omitted
> any I.D. of this person, but thought I must document this ;
>
> Bio-Rad, TSS phone conversation 12/28/04
>
> Finally spoke with ;
>
>
> Bio-Rad Laboratories
> 2000 Alfred Nobel Drive
> Hercules, CA 94547
> Ph: 510-741-6720
> Fax: 510-741-5630
> Email: XXXXXXXXXXXXXXXXXX
>
> at approx. 14:00 hours 12/28/04, I had a very pleasant
> phone conversation with XXXX XXXXX about the USDA
> and the inconclusive BSE testing problems they seem
> to keep having. X was very very cautious as to speak
> directly about USDA and it's policy of not using WB.
> X was very concerned as a Bio-Rad official of retaliation
> of some sort. X would only speak of what other countries
> do, and that i should take that as an answer. I told X
> I understood that it was a very loaded question and X
> agreed several times over and even said a political one.
>
> my question;
>
> Does Bio-Rad believe USDA's final determination of False positive,
> without WB, and considering the new
> atypical TSEs not showing positive with -IHC and -HP ???
>
> ask if i was a reporter. i said no, i was with CJD Watch
> and that i had lost my mother to hvCJD. X did not
> want any of this recorded or repeated.
>
> again, very nervous, will not answer directly about USDA for fear of
> retaliation, but again said X tell
> me what other countries are doing and finding, and that
> i should take it from there.
> "very difficult to answer"
>
> "very political"
>
> "very loaded question"
>
> outside USA and Canada, they use many different confirmatory tech. in
> house WB, SAF, along with
> IHC, HP, several times etc. you should see at several
> talks meetings (TSE) of late Paris Dec 2, that IHC- DOES NOT MEAN IT IS
> NEGATIVE. again, look what
> the rest of the world is doing.
> said something about Dr. Houston stating;
> any screening assay, always a chance for human
> error. but with so many errors (i am assuming
> X meant inconclusive), why are there no investigations, just false
> positives?
> said something about ''just look at the sheep that tested IHC- but were
> positive''. ...
>
>
> TSS
>
> -------- Original Message --------
> Subject: Your questions
> Date: Mon, 27 Dec 2004 15:58:11 -0800
> From: To: flounder@wt.net
>
>
>
> Hi Terry:
>
> ............................................snip Let me know your phone
> number so I can talk to you about the Bio-Rad BSE test.
> Thank you
>
> Regards
>
>
>
> Bio-Rad Laboratories
> 2000 Alfred Nobel Drive
> Hercules, CA 94547
> Ph: 510-741-6720
> Fax: 510-741-5630
> Email: =================================
>
>
> END...TSS
>
>
Audit Report
Animal and Plant Health Inspection Service
Bovine Spongiform Encephalopathy (BSE) Surveillance Program – Phase II
and
Food Safety and Inspection Service
Controls Over BSE Sampling, Specified Risk Materials, and Advanced Meat Recovery Products - Phase III
Report No. 50601-10-KC January 2006
Finding 2 Inherent Challenges in Identifying and Testing High-Risk Cattle
Still Remain Our prior report identified a number of inherent problems in
identifying and testing high-risk cattle.
snip...
NOW, Back to this very important document, and what i suspected back then was suspicious, and sure enough, years later, i find this document;
BSE research project final report 2005 to 2008 SE1796 SID5
Executive Summary
7. The executive summary must not exceed 2 sides in total of A4 and should be understandable to the intelligent non-scientist. It should cover the main objectives, methods and findings of the research, together with any other significant events and options for new work.
Studies of Bovine Spongiform Encephalopathy (BSE), carried out in the UK, showed it to be a single strain of prion disease based on histopathological (Simmons et al., 1996) and transmission data (Bruce et al., 1992 ). First reported in the 1980s (Wells et al., 1987) there appears to have been little change in the characteristics of the disease throughout the epidemic and BSE maintains a distinct molecular profile even following cross species transmission. However, during surveillance programmes in Europe and in North America two other distinct isolates of bovine prion disease have come to light, H and L type, so-called to reflect their unique molecular profiles (Yamakawa et al., 2003; Biacabe et al., 2004).
Reports were also emerging of atypical forms of scrapie that were distinct from classical scrapie isolates and were less easily recognised by the then current diagnostic tests (Benestad et al., 2003; Buschman et al., 2004). This led to concerns that cattle could also harbour a prion disease that was not detected by the current diagnostic tests for BSE. Importantly, approximately 15-20% of the clinical cases submitted for investigation were indeed negative and this proportion of negative cattle did not appear to vary despite increasing awareness of BSE clinical signs by the farming and veterinary community. While there maybe other explanations for this discrepancy (McGill et al., 1993), another underlying undiagnosed prion disease of cattle distinct from classical BSE could not be ruled out.
The study reported here investigated a small number of these BSE negative clinical cases by using more sensitive and modified diagnostic tests for abnormal PrP.
The majority of the cases that we studied were negative by all the tests employed and based on this observation we conclude that there was not a simultaneous epidemic of another form of bovine prion disease. However, we observed a number of classical cases that were missed prior to the advent of sensitive and rapid diagnostic tests and this provides an estimate of the number of cattle that were mis-diagnosed before 2000. In addition, we observed a few rare cases where the diagnostic tests were not in agreement and these cases were investigated further. One of these unusual samples emerged as a case of idiopathic bovine neuronal chromatolysis (IBNC).
During the study we also reported the first H-type BSE case in the UK (Terry et al., 2007).
snip...
Scientific Objectives as prescribed in the project:
All of the objectives have been met and are described in detail below. Three annexes accompany this report, one with the figures for the results below and two papers for submission to peer-reviewed journals.
Objective 1: To determine the variation of PK sensitivity of bovine PrPc from uninfected cattle brains and compare with bovine PrPsc from classical cases of BSE in order to set thresholds for negative, weak and strong positive values in commercially available rapid diagnostic tests. Objective 2: Determine whether there are a greater proportion of bovine brain samples positive for the rapid diagnostic tests (hereby called reactors) in the clinically-suspect, negative subset of cattle than in healthy negative cattle. (True positives will be determined on the basis of evaluation by IHC but should be strongly positive in both the rapid diagnostic tests). Objective 3: Determine whether the phenotypic and molecular characteristics of PrP from cattle identified in 2 are distinct from normal PrPc and from bovine PrPsc normally associated with classical BSE. Studies of Bovine Spongiform Encephalopathy (BSE), carried out in the UK, showed it to be a single strain of prion disease based on histopathological (Simmons et al., 1996) and transmission data (Bruce et al., 1992). First reported in the 1980s (Wells et al., 1987) there appears to have been little change in the these characteristics of the disease throughout the epidemic; BSE also appear to maintain a distinct molecular profile in cattle and even when experimentally (or naturally) transmitted to other species such as humans and cats. However, during surveillance programmes in Europe, Japan and in North America, two other distinct isolates of bovine prion disease have come to light, H and L type, so-called to reflect their unique molecular profiles (Yamakawa et al., 2003; Biacabe et al., 2004). In the late 1990’s, a novel prion disease was discovered in sheep (Benestad et al., 2003; Buschman et al., 2004); this Nor98 or atypical scrapie is widespread in Europe but had previously been missed by histopathological or immunohistological examination. This led to concerns that cattle could also harbour a prion disease that, unlike H- and L-type BSE, was not detected by the current diagnostic tests for BSE. Importantly, approximately 15-20% of the clinical cases submitted for investigation were indeed negative and this proportion of negative cattle did not appear to vary despite increasing awareness of BSE clinical signs by the farming and veterinary community. While there maybe other explanations for this discrepancy (McGill et al., 1993), another underlying undiagnosed prion disease of cattle distinct from classical BSE could not be ruled out. The study reported here investigated a small number of these BSE negative clinical cases by using more sensitive and modified diagnostic tests for abnormal PrP. The majority of the cases that we studied were negative by all the tests employed and based on this observation we conclude that there was not a simultaneous epidemic of another form of bovine prion disease. However, we observed a number of cases of BSE in this “BSE negative” sub-set that were missed prior to the advent of more sensitive and rapid diagnostic tests and this provides an estimate of the number of cattle that were mis-diagnosed before 2000. In addition, we observed a few rare cases where the diagnostic tests were not in agreement and these cases were investigated further. One of these unusual samples emerged as a case of idiopathic bovine neuronal chromatolysis (IBNC) (Jeffrey & Wilesmith, 1992; 1996; Jeffrey et al., 2009). During the study we also reported the first H-type BSE case in the UK (Terry et al., 2007). Materials and Methods Tissue samples. Test samples: Frozen brain stem from 501 bovine BSE suspects with neurological signs, a) that were negative at the level of the obex for vacuolation by standard histopathological techniques from years 1991-1999 and b) by IHC and diagnostic Bio-Rad PlateliaTM from 2000 onwards. These tissues have been stored at the VLA at –80oC since submission.
Negative controls: Frozen brain stem from 90 cattle investigated as part of the active surveillance programme. These samples were submitted in 2006 to LGC for rapid testing by Bio-Rad TeSeE diagnostic ELISA and were negative. These samples were stored at –80oC prior to testing and were stored for a maximum of 36 months and therefore considerably less time than all experimental samples under investigation.
Cattle with suppurative encephalitis: 10 additional cattle samples were retrieved from the VLA Archive that were negative for BSE but showed signs of suppurative encephalitis and inflammation (lymphocyte cuffing and gliosis). These signs were consistent with listeria infection.
Tests for disease-associated PrP IDEXX BSE Herdchek BSE antigen test kit
All samples were assayed using the IDEXX Herdchek Bovine Spongiform Encephalopathy (BSE) Antigen Test Kit, EIA according to the manufacturer’s instructions and without modification. Briefly, brains were homogenised in the buffer provided by the manufacturer and diluted prior to adding to the seprion (polyanion) coated multiwell plate and incubated prior to washing. The samples were then treated with a conditioning buffer to expose the antigen epitopes. PrPsc was detected by PrP specific antibodies conjugated to horseradish peroxidase and visualised with TMB substrate. Samples were read using a microtitre plate reader (Victor-Perkin-Elmer). The method has no Proteinase K digestion step and has only a mild trypsin treatment that is not required for specificity but aids in the epitope exposure step. The normal curve of negative control samples is provided by the manufacturer and shows the diagnostic cut off value is set higher than most negative controls. The amount of brain added to a single well is approximately 20 mg. Diagnostic Bio-Rad TeSeE EIA
Sample extraction and detection was carried out according to the manufacturer’s instructions for the Bio-Rad TeSeE BSE ELISA. Briefly brain samples were homogenised in buffer provided by the manufacturer and then treated for 10 mins with Proteinase K at 37oC . The PK concentration is not provided by the manufacturer so we refer to it as 4 ul/ml which is the quantity of stock PK to final solution directed by Bio-Rad. A comparison with sigma PK indicated that the concentration is approximately 40 ug/ml. The samples were then precipitated and concentrated by centrifugation. Pellets were reconstituted and diluted in the buffers provided by the manufacturer. The PrPsc was then detected by a sandwich ELISA provided by the manufacturer. Details of the antibodies are not provided. Samples are read using a microtitre plate as above. Cut off values for the ELISA are calculated using the mean of four negative control ODs. The manufacturers indicate that a value of 0.14 should be added to the negative control mean and samples equal to or greater than this value should be further analysed. The amount of brain added to a single well is approximately 65 mg. BioRad TeSeE EIA with reduced PK digestion (0.3 Bio-Rad TeSeE ELISA)
The PrPsc associated with atypical scrapie is believed to be less PK resistant than classical scrapie (Everest et al., 2006). In order to investigate whether an atypical form of BSE in cattle exists biochemically similar to atypical scrapie a modified version of the Bio-Rad TeSeE protocol, using sub-diagnostic levels of Proteinase K (0.3ul/ml), was used. This quantity of PK was arrived at by titration of PK and digestion of PrPc from 47 cattle brains negative for TSEs.
The Bio-Rad TeSeE BSE diagnostic test was used as directed by the manufacturer with the addition of DNAse prior to the Proteinase K (0.3 ul/ml PK) treatment and Pefabloc was added alongside the kit PK stopping solution. The PK dilution for these assays was prepared from a Sigma stock solution and 0.3 units/ml was the equivalent activity as 0.3 ul/ml of Biorad PK. Bio-Rad TeSeE Western Blot
Sample extraction was carried out according to the manufacturer’s instructions (Bio-Rad TeSeE Western Blot) with several modifications. In brief, brain tissue was ribolysed to give 20 % (w/v) homogenate and subsequently incubated with DNAse. The samples were then digested with 0.3, 1, 4 or 20 units/ml PK (Sigma; where units/ml is an in-house nomenclature and 0.3 units/ml is equivalent to 0.3 µl of the Bio-Rad test PK in terms of activity as compared using the TAME test -Pierce) and the reaction stopped with Pefabloc. Following precipitation and centrifugation at 15,000 g for 7 minutes, in accordance with the Bio-Rad TeSeE Western blot protocol, the pellets were re-suspended in Laemmli sample buffer.
For analysis, the supernatants were heated at 100oC for 5 minutes, loaded on a 12% Criterion XT Bis-tris SDS gel (Bio-Rad) and subjected to electrophoresis in XT-MOPS running buffer (Bio-Rad) at 200 V for 50 minutes. Proteins were transferred to a PVDF membrane (Bio-Rad) at 115 V, 60 min using Tris/CAPS transfer buffer (Bio-Rad).
Blots to be evaluated using the Sha31 (Bio-Rad) antibody were incubated for one hour with the blocking solution provided by the manufacturers; and antibodies SAF84 (aa 175-180), P4 (aa 89-104) and FH11 (aa 55-65) using a 5% milk powder in PBS supplemented with Tween 20 (PBST). The membranes were incubated for one hour with the primary antibody and then with goat anti-mouse IgG antibody conjugated to horseradish peroxidase (Bio-Rad) prior to visualization by chemiluminescence (ECL; Amersham). Immunohistochemical analysis Formalin-fixed, paraffin wax-embedded tissue blocks were sectioned at 4mm, collected onto frosted charged slides (GmbH) and melted on at 60°C overnight to improve adhesion. Sections were de-waxed in xylene and alcohol and washing in water. They were subsequently put into 98% formic acid (Merck) for 30 minutes, washed in running tap water for 15 minutes and then fully immersed into citrate buffer (200mM trisodium citrate dehydrate (Sigma), 30mM citric acid (Sigma), pH 6.1) prior to being autoclaved for 30 minutes at 121°C. Endogenous peroxidase activity was quenched using 3% hydrogen peroxide (Sigma) and the sections immersed in purified water and stored at 4°C overnight. After warming to room temperature, non-specific antibody binding sites were blocked using normal goat serum (Vector Laboratories) for 20 minutes. Rat monoclonal anti-PrP R145 (VLA) was diluted to 2mg/ml and applied for one hour at ambient (19°C-24°C) temperature. Biotinylated rabbit-anti-mouse IgG (Vector Laboratories) was diluted appropriately and applied for 30 minutes at ambient temperature. Elite ABC (Vector Laboratories) was prepared according to the manufacturers’ directions and applied for 20 minutes at ambient temperature. Sections were washed between each stage using 5mM tris buffered saline supplemented with Tween-20 (5mM tris, 0.85% NaCl, 0.05% tween-20 (all from Sigma), pH 7.6). Diaminobenzidine tablets (Sigma) were prepared in McIlvanes buffer (200mM disodium hydrogen orthophosphate, 100mM citric acid (both from Sigma), pH 6.4) and applied for 10 minutes at ambient temperature. Sections were counterstained in Mayer’s haematoxylin and “blued” in running tap water, before being dehydrated through three changes each of absolute alcohol and xylene for three minutes each and finally mounted in DPX (Sigma). Definition of terms
Disease associated isoforms of PrP may be distinguished from normal PrP by its increased resistance to Proteinase digestion in immunoblotting or ELISA tests (PrPres), binding to polyanions or labelling with PrP specific antibodies in fixed and treated paraffin-embedded section (PrPd). Included within the operational definition of PrPd are all those detection systems that do not use Proteinase K digestion. The correlation between prion infectivity and PrPres or PrPd is inexact, and infectivity has been dissociated from PrPres or PrPd in several experiments, putatively this is because only a fraction of abnormal PrP isoforms are infectious. We will therefore use operational definitions for detected abnormal PrP forms and PrPsc for the hypothetical infectious sub-population of PrP isoforms detected by bioassay. Results Brains from cattle previously diagnosed as negative for BSE based on histopathological examination were investigated in this study for evidence of unusual prion diseases. The majority of the cattle investigated were submitted to the VLA as BSE suspect during the years 1997-2005 and were reported to have clinical signs similar to BSE. We applied a combination of modified and previously unused diagnostic tests to this subgroup of cattle including lower concentrations of PK for protein digestion, tests that do not use PK for PrPsc detection and standard Western blot (WB) procedures with Mabs reactive with different regions of the PrP glycoprotein. A flow chart detailing the sequence for the investigation of potential unusual prion diseases of cattle are shown in Figure 1. 1) Determination of the lowest PK concentration that digests PrPc from brains of cattle The minimum concentration of PK required for the elimination of PrPc in the majority of non-exposed control cattle samples, resulting in a negative value in the Bio-Rad TeSeE ELISA, was determined. PK titrations were performed on BSE positive and negative control reference material (CRM) and subsequently on 47 individual confirmed negative brainstems. The brainstems had previously tested negative with the diagnostic Bio-Rad TeSeE ELISA by LGC and were obtained from active surveillance and therefore unlikely to have had clinical signs of disease. An amount of 0.3 µl/ml PK was selected for use in the adapted Bio-Rad TeSeE ELISA (0.3 Bio-Rad) (Table 1). 2) Determination of threshold values for the IDEXX HerdChek and 0.3 modified Bio-Rad rapid tests
The diagnostic tests have cut-off values that are set by the manufacturers. For the 0.3 Bio-Rad ELISA new cut-off values were determined to take account of the modifications. While no modifications were made to the IDEXX HerdChek assay cut-off values were calculated using the same test samples for consistency. 90 confirmed BSE negative brainstems were assayed and threshold values calculated as 3 standard deviations above the mean (Table 2). Threshold values of 0.166 Absorbance Units (AU) and 0.137 AU were set for the 0.3 Bio-Rad TeSeE and IDEXX Herdchek EIAs respectively. A single confirmed negative sample gave a value above the IDEXX threshold limit (0.240AU) on first assay. However, when repeated this sample was negative (0.016AU). 3) Results of assays applied to the test BSE cattle population
The assays described above and mapped in Figure 1 were then applied to the brains from 501 clinically suspect cattle. Following analysis the cattle were divided into five groups and these are described below. The results are summarised in Table 3. Group1: Confirmed negative diagnosis of clinically suspect cattle Brainstems from 501 cattle submitted to the VLA for BSE diagnosis between the years 1991 and 2005 that were subsequently diagnosed as negative by the tests used at time of slaughter, were assayed using the IDEXX and 0.3 Bio-Rad immunoassays for detection of abnormal PrP. 436 (87%) were negative by both tests. All of the samples submitted after 1999 were confirmed negative (see below) (Figure 8). By these criteria we were unable to detect abnormal PrP in the brainstems of these cattle and this subset of clinically suspect cattle is unlikely to harbour a prion disease. However, we were unable to test other areas of the brain from these cattle and PrPsc distribution patterns distinct from classical BSE cannot be ruled out. In addition to the 501 brainstems we also tested 191 cerebella by the same methods, all of which were negative by standard tests. Group 2: Confirmed positive for BSE by all diagnostic tests Sixty five samples remained that were positive in either the IDEXX or the 0.3 Bio-Rad assays or in both of these tests. Of these, 40 were positive by both tests (modified as above) and following retesting were positive using diagnostic concentrations of PK for the Bio-Rad TeSeE (figure 2). Immunohistochemical evaluation of abnormal PrP in the obex demonstrated normal distribution of PrPsc deposits similar to those observed for classical BSE (Figure 8).
To confirm that the PK resistant glycoproteins of abnormal PrP resembled the molecular profile of classical BSE, all 40 cases were immunoblotted using SHa31 MAb (figure 3). In all cases a signature 3 glycoprotein banding pattern was observed with relative mass and glycoprotein ratios indistinguishable from classical BSE. These animals ranged in age from 5 years to 12 years, with a mean age of 6 years, 10 months. All 40 animals were female and comprised 32 Friesians, 2 Holsteins, 2 Herefords, 1 Limousin/Friesian Cross, 2 Holstein/Friesian Cross and 1 Simmental.
The 40 confirmed positive samples were from cattle slaughtered between the years 1997 and 1999. We tested a total of 285 from this period and this represents 14.0% of the clinical suspects that were confirmed negative for BSE at this time. If this is representative of the entire clinical suspect unconfirmed cattle (total 2,426) during this period (1997-1999 inclusive) a total of 340 BSE positive cattle would have been missed. This under-diagnosis is likely to be a result of the diagnostic tests applied at the time. Up until the year 2000, all BSE cases were diagnosed by detection of vacuolation and gliosis in the obex. It is clear that this method is not 100% sensitive for prion diseases either because not all cases present with vacuolation or that vacuolation is a late onset phenomenon during clinical disease (Arnold et al., 2007). Our data showed that there were no additional cases of under-diagnosis after more sensitive diagnostic tests were introduced in 2000. During the years 1997-1999, a total of 12,171 clinical cases were submitted for BSE diagnosis of which 9,745 (80.1%) were confirmed positive with an estimated 2.8% of the total suspects submitted under-diagnosed by our calculations.
Assuming no other factors influenced the levels of correct diagnosis and that the numbers estimated for 1997 to 1999 were a true representation of the potential under-diagnosis of the entire epidemic up until 1999, then the total number of missed cases positive for BSE could have been in the region of 5,500.
A draft version of this manuscript has been prepared.
Group 3: Confirmed positive for BSE by all rapid diagnostic tests but negative by IHC
2 of the 501 negative subset brainstem tested were positive by standard biochemical, diagnostic tests (Table 4) but abnormal PrP deposits were not observed in the obex when evaluated by IHC (Figure 8). This is clearly an unusual finding and both cases were rigorously audited prior to further investigation to determine that the sample for biochemistry was identical to the paraffin-embedded sample. As far as can be determined no errors in sampling and dispatch occurred for these two samples. Further DNA profiling and matching frozen sample to histology processed sample would confirm this. There was insufficient sample to perform any further analysis on one case, but the other case was further investigated using the modified TeSeE Western blot protocol described above – at the diagnostic standard PK concentration of 4 µl/ml for PrPsc digestion. Western blotting of abnormal PrP from this sample confirmed the ELISA data with intense labelling of PK resistant PrP using the PrP-specific antibodies Sha31 and SAF84 (Figure 4a and 4b). The glycoprofile and molecular mass of the PrP bands were indistinguishable from classical BSE A band was labelled strongly with FH11 Mab (that recognises an N terminal PrP epitope) and is therefore likely to represent undigested PrP (Figure 4c). In addition, at 4 µl/ml PK, strong reactivity is also observed with the P4 mAb (Figure 4d). Molecular comparison of this case with classical BSE and with scrapie – using different levels of PK, different dilutions of positive sample and different PrP-specific antibodies, indicates that there is no discernible difference of the test sample with classical BSE. Both cases were extensively followed up by IHC using Mabs to different regions of the PrP molecule but were negative in all cases (data not shown).
Why the PrPsc could not be detected by IHC is unclear. Further analysis by transmission to rodent models of prion disease may shed further light on the characteristics of this sample. Indeed, murine models of prion disease have been reported where PrPsc cannot be detected in the brains but these studies confirmed the lack of PrPsc by all assays including Western Blot. Group 4: IDEXX Herdchek positive, 0.3 Bio-Rad negative, IHC positive. Two brainstem samples (98/00819; 98/02316) were positive by the IDEXX Herdchek EIA (Table 5) but Bio-Rad test negative even following PK digestion at sub-optimal concentrations. Both of these samples demonstrated abnormal PrP deposition in the obex by IHC evaluation (Figure 8). Western blot analysis of PK resistant PrP glycoprotein from sample 98/2316 indicated that low amounts of PrPres could be detected using Sha31 and SAF84 Mabs. From these blots and taking into account the low levels of PrPres detected the banding patterns appeared indistinguishable from classical BSE (Figure 5a and 5b). No further sample was available for 98/00819. The sample contained very low levels of PrPres as shown by the WB data and this is likely to be the reason for lack of signal in the Bio-Rad ELISA. At these levels of abnormal PrP we are at the threshold of detection. The IDEXX HerdChek assay has consistently shown a higher analytical sensitivity for classical scrapie in our hands than the Bio-Rad assays. The values for the IDEXX HerdChek were in the region of 0.15-0.88 and these values are much lower than any of the other samples we have tested in this study. These data suggest that the IDEXX assay is more analytically sensitive than the Bio-Rad TeSeE for BSE. However, there are alternative explanations for the discordance in test results. The Bio-Rad TeSeE ELISA detects PrPres with Mabs that detect 2 regions of the molecule. Any changes in PrP sequence in the region of Mab binding could alter analytical sensitivity. Therefore the bovine PrP open reading frame from 98/02316 was compared with that of two classical BSE samples, all three samples were 6:6 with respect to the octapeptide repeat. The only mutation seen in this unusual sample was at codon 78 and this is a “silent” mutation in that it does not affect the PrP protein sequence (glutamine, Q78). The Western blot results suggest that the PK cleavage sites of sample 98/02316 were not different from classical cases of BSE. Therefore we conclude that PrPres concentration in this sample was low, as indicated by the control BSE positive brain homogenate, when diluted to a level of 1/250, still producing bands of a far greater density than the test sample when assayed neat. Group 5: Diagnostic Bio-Rad and IDEXX negative, IHC negative but 0.3 Bio-Rad positive
Twenty-one of the clinical suspect brainstems tested by 0.3 Bio-Rad modified protocol had OD values above the calculated cut off point (range 0.166 to 0.857) (Figure 6) but were IDEXX Herdchek negative and IHC negative (figure 8). The samples were also diagnostic Bio-Rad TeSeE negative and the cattle, all female, ranged in age from 3 years to 11.5 years. They comprised Friesian, Friesian/Holsten, Hereford Cross, Aberdeen Angus Cross, Simmental Cross and Limousin Cross breeds. These samples, where sufficient tissue was available, were analysed, for the presence of partially PK resistant PrP, using the Bio-Rad Western blot protocol with digestion carried out at 20 and 0.3 µl/ml of PK and detected using the SHa31 Mab. Following digestion of the samples with 20 µl/ml PK the samples were shown to be negative for the characteristic PrPsc banding patterns when compared to three individual BSE-negative samples and a classical BSE positive sample (Fig 7a). However, faint bands were observed at approximately 16 and 25 KDa for 4 of the samples (T5, T8-T10) but this faint banding is consistent with partially digested PrPc but could also be a result of variable amounts of protein loaded per lane. At 0.3 µl/ml PK, banding is observed for all test samples, with banding consistent with partially digested PrPC, as also observed for the three known BSE-negative samples. In contrast, the classical BSE-positive sample gave a distinct banding pattern, different from that observed for the BSE-negative samples (Fig.7b). Consistent with the above results samples T5 and T8-T10 demonstrated increased intensity of labelling that could result from an up-regulation or increase in PrPc and could also account for the high signals in the modified ELISA.
Variable banding intensity between lanes may also be a result of inconsistent loading of amounts of protein per lane. However, our previous experience of testing protein concentrations PRIOR to PK digestion in the individual samples showed that they were very consistent to within <5% of the total amount. In addition, although we add pefabloc to stop PK digestion it is also likely that there is variation in the PK digestion amongst samples. Both variables could account for the differences in intensities between lanes. However, we cannot exclude the possibilitity that a PK sensitive variant of abnormal PrP is present as demonstrated by Barron et al 2007 who also demonstrated a 22 KDa band following sub optimal PK digestion. The samples were further investigated as below. Encephalitis may up regulate PrPc
One explanation for high values in the immunoassay following digestion with suboptimal concentrations of PK could be high levels of PrPc in the sample. Increased levels of PrPc may occur as a result of up-regulation of PrPc on tissue resident cells or from the influx of inflammatory cells into the site following infection. Differential diagnoses were available for 9 of the 21 animals and nine had confirmed encephalitic lesions and inflammation. Further to this observation we therefore analysed brainstems from 10 BSE negative cattle (but also clinical suspects) by both modified rapid tests that had confirmed encephalitis.
The brainstems from 9 encephalitis cattle were negative by both the 0.3 Bio-Rad TeSeE and IDEXX assays. The brainstem from 1 animal was positive by the 0.3 Bio-Rad assay but negative by the IDEXX EIA. The result from this sample is similar to the 21 observed above in group 5. It is unclear therefore whether the high levels of PrP are a result of concurrent infection as there is not a 100% correlation. However, PrPc is more susceptible to endogenous proteases and a low signal could be partly explained by inappropriate handling of the tissue at post-mortem. Loss of PrP detection following retesting of group 5 samples.
When all 21 samples were re-analysed from a fresh piece of tissue from the archive (likely to have been frozen and thawed by the archive staff) only one retested as positive (figure 6). Further analysis of this sample (sample number 99/00514) by Western blot has not shown any bands suggesting the presence of an atypical form of prion protein. Any PK sensitive PrP, whether PrPc or unusual prion disease-associated PrP, is likely to be affected by tissue handling techniques including freezing, thawing and the amount of time in storage. This could explain loss of signal. These samples may also represent a small number of outliers in the negative population. This is still higher than we would expect given that only 1/90 negative control samples were outliers in the original testing. Identification of Idiopathic Brainstem Neuronal Chromatolysis (IBNC) in group 5 samples One of the 21 samples identified in group 5 was shown to have IBNC following histological investigation (03/00002) (figure 8). Concurrently, we investigated the PrP distribution in known cases of IBNC (Jeffrey et al 2008; “Idiopathic Brainstem Neuronal Chromatolysis (IBNC): a novel prion protein related disorder of cattle?” BMC Vet Res. 2008 Sep 30;4:38. The IHC and histology profile of this case was very similar to that of the known IBNC cases. Investigation of the distribution and molecular characteristics of PrP from known IBNC See also: Idiopathic Brainstem Neuronal Chromatolysis (IBNC): a novel prion protein related disorder of cattle? Jeffrey M, Perez BB, Martin S, Terry L, González L. BMC Vet Res. 2008 Sep 30;4:38 Further investigations demonstrated that 57% the assays performed on the confirmed IBNC samples, using the 0.3 Bio-Rad TeSeE assay (n=42), gave values above those of the test kit control and also the BSE negative brain pool control. Half brains from six IBNC affected animals were retrieved from the TSE archive alongside the brainstem from a seventh animal. The cortex, brainstem, cerebellum and midbrain from these brains were sub-sampled and the adapted Bio-Rad TeSeE EIA, IDEXX Herdchek and Western Blot protocols applied to these tissues, in order to determine whether they could represent a form of atypical BSE. These samples had previously been found to be negative using the commercial Bio-Rad EIA and re-testing using this assay and the IDEXX Herdchek assay confirmed their negative status. When assayed using the adapted Bio-Rad protocol at 0.3µl/ml PK, 24/42 (57%) of the sample assays performed gave values above those of the test kit control and also the BSE negative brain pool control. Values above twice that of the calculated cut-off levels were found for each case but not for each brain site No PrPres was detected when Western blotting these samples at either 20 or 4µl/ml PK but a signal was detected on the gels when blotted at the 0.12 and 0.3µl/ml PK levels. At 0.12µl/ml PK the IBNC samples were indistinguishable from the negative controls but at the 0.3µl/ml level more PrPres was detected in the IBNC cases than in the controls with each of the antibodies tested (SHA31, F99, SAF84 and P4). Illustrations of the F99 blot are shown in the paper. Other data not shown.
These data suggest that IBNC affected cattle abnormally express or accumulate PrP in brain and that the abnormal PrP is not strongly resistant to protease digestion. The results suggest that either the range of prion diseases is still wider than previously thought or that abnormalities of prion protein expression may be associated with brain lesions unconnected with prion disorders. Biochemical and transmission studies are planned in order to investigate further (under SE2014). First case of H-type BSE identified in GB During the course of this study, 1/5 frozen brainstem from bovine BSE cases when immunoblotted using the Bio-Rad TeSeE Western blot with antibodies P4, L42, 6H4, Sha31 and SAF84, was found to have a PrP profile indistinguishable from French H-type BSE. This sample was the first case of H-type BSE to be identified in GB. It was a fallen 13-year-old Galloway cow, first tested and confirmed as a case of BSE in November 2005. Due to autolysis its brain was unsuitable for further characterisation by IHC. Its age and reported absence of clinical signs are consistent with other cases of H-type BSE.
When blotting the samples, mAbs Sha31 and 6H4 revealed, in this sample, an unglycosylated band with relative mobility less than BSE, and mAb P4, labelled the sample more strongly than the BSE samples hence supporting the observed similarities with the French H-type sample. Additionally, this study revealed in both this unusual sample and the French H-type a lower molecular weight band with relative mobility of between 6 and 10 kD labelled with the P4 and L42 mAbs. This band is not seen in BSE samples. This data was published in June 2007 (L. A. Terry et al. Veterinary record (2007) 160, 873-875). Discussion and Conclusions Here we report the investigation of 501 cattle samples that were submitted to the VLA for BSE diagnosis but subsequently confirmed as negative by the diagnostic test used at the time of submission. Prior to 2000 this was by histology alone and positive diagnosis was made solely upon the observation of vacuolation and gliosis in the relevant brain regions. As a result, using more sensitive diagnostic assays, we were able to diagnose BSE positive cattle from the years 1997-1999 inclusive that were originally negative by vacuolation. From these data we have estimated that approximately 3% of the total suspect cases submitted up until the year 1999 were mis-diagnosed. This is likely to be due to the relative sensitivities of the methods. In addition, it has been demonstrated in cattle that vacuolation occurs after PrPsc can be detected in the brain stem and that PrPsc is detected prior to clinical disease (Arnold et al, 2007). Thus these cattle may have suffering very early clinical signs. However, we have not ruled out the possibility that there may be a subset of BSE affected cattle where vacuolation at the obex does not occur. The two cattle that were positive by the rapid biochemical tests but negative by IHC is an unexplained observation. The samples both contained high amounts of abnormal prion protein as determined by the OD values from the rapid tests that according to our experience of confirmatory testing should have been easily detected by IHC. Furthermore, epitope mapping of the PK cleaved proteins demonstrated no unusual glycoform patterns and IHC evaluation with the same antibodies still did not reveal PrPd deposition in the wax embedded sections. Thus it is unlikely that lack of detection by IHC is the result of an unusual conformation of the PrPd that masks the epitope of R145, the antibody of choice for IHC evaluation at the VLA.
The two cattle that were positive by all tests except Bio-Rad ELISA are easier to explain. Previously we have demonstrated that the IDEXX HerdChek scrapie antigen EIA is more analytically sensitive for scrapie than the Bio-Rad ELISA (project SE2007) and this also appears to be the case for bovine BSE. Indeed the two samples were positive by the Bio-Rad Western blot but with significantly reduced signals compared to a bovine positive control. Samples in group 5 were only positive in the Bio-Rad ELISA and only if sub-optimal concentrations of PK were used. Several explanations could account for this result. First, the samples may contain a subset of PrP molecules that have a slightly higher resistance to PK digestion than normal PrPc and that it is not sufficiently aggregated to be detected by the IDEXX assay; whether this is related to a prion disease or some other event that confers such properties on normal PrP remains unanswered. There are notable descriptions in the literature of TSE models where disease is not accompanied by the characteristic accumulation of PK resistant PrP or was found at extremely low levels (Piccardo et al., 2007; Barron et al 2007; Nazor et al., 2005). These findings together might suggest an additional family of neurodegenerative diseases where the infectious form of PrP is not readily detected by our current diagnostic tests.
Second, the higher signal could be the result of an increase in the overall amount of PrPc in the samples as discussed in the results and related to up-regulation of PrP in cells resident in the brain or due to influx of inflammatory cells either as a result of damage or the presence of a non-prion related disease. Third, that the PrP in these samples is bound to an unidentified molecule that confers higher PK resistance, or fourth, inhibits proteinase K. IBNC is likely to represent a subset of this group of cattle. Based on these data, our overall conclusion is that a second type of BSE is unlikely to have co-existed at a high prevalence with the classical form in the cattle population during the UK epidemic.
Final Report - Annex : Atypical prion proteins in cattle (10064k)
Final Report - SID5 : Atypical prion proteins in cattle (201k)
USDA announces expanded BSE surveillance program Filed Under: BSE
By: Marty Heiberg | Mar 15, 2004 Editor's note: Some material was added to this story Mar 16.
Mar 15, 2004 (CIDRAP News) – Secretary of the US Department of Agriculture (USDA) Ann Veneman this afternoon announced an expanded program of surveillance for bovine spongiform encephalopathy (BSE) in the United States. Preparations for the increased testing will begin immediately and the program is expected to be fully operational by June 1. The new testing procedures will be in place for 12 to 18 months, after which an assessment will determine future plans.
"The intensive one-time surveillance effort will allow us to determine more accurately whether BSE is present in the US cattle population, and if so, estimate the level of disease. By expanding our surveillance, we will be able to provide consumers, trading partners, and industry increased assurances about the BSE status of the U.S. cattle population," states the new plan, which was published on the USDA Web site today.
The new plan incorporates last month's recommendations from the international scientific review panel and it is supported by the Harvard Center for Risk Analysis, Veneman said at a press briefing. It calls for testing a much larger number of specimens from the high-risk BSE cattle population than the current 40,000 per year as well as about 20,000 random samples from normal-appearing adult cows.
Cattle at high risk for BSE are estimated to number approximately 446,000 currently in the United States. The definition of high risk, based on experience in the United Kingdom and Europe, includes adult cattle that are nonambulatory ("downers"), dead on the farm, or showing clinical signs consistent with BSE.
Ron DeHaven, the USDA's chief veterinary officer, said at the briefing that the expanded program would mean testing "as many as we possibly can" of the target population of cattle. He explained that the new testing would allow for identification of BSE at a rate of 1 in 10 million cattle with a confidence level of 95% if 201,000 samples were tested and a confidence level of 99% if 268,000 samples were tested.
Testing will be done at 17 state and university laboratories, with confirmation of any positive results at the National Veterinary Services Laboratory in Ames, Iowa. Funding for the new program totals $70 million.
When questioned about proposals to test 100% of cattle, DeHaven said that science does not justify this level of testing and that, while the USDA is still evaluating the proposals, testing at this level would be solely for marketability and export purposes. The USDA's newly enhanced program, he said, is strictly for surveillance purposes and will determine whether and at what level BSE exists in the target cattle population.
DeHaven said the expanded testing program will rely on rapid screening tests, several of which the USDA is currently evaluating. "We would anticipate in two or three months' time being able to license perhaps a couple or more of those tests," he said.
Because the screening tests are designed to be very sensitive, some false-positive results are expected, DeHaven said, adding, "That's just the nature of the beast." The national laboratory in Ames will use immunohistochemical staining, considered the "gold standard" in BSE testing, to confirm any positives.
DeHaven said the USDA has made no decision yet on the proposal by Creekstone Farms of Arkansas City, Kan., to test all its cattle so the beef can be exported to Japan and other Asian markets.
The USDA will collect samples from high-risk cattle at a variety of places, including federally inspected slaughter plants, farms, rendering plants, veterinary diagnostic laboratories, pet food plants, and livestock sale barns, DeHaven said.
To test a random sample of healthy older cattle, the USDA will focus its main efforts on 40 slaughter plants in 17 states, according to DeHaven. Those plants slaughter more than 86% of all cattle in the nation, he said.
Under questioning, DeHaven refused to give a specific target for the number of high-risk cattle to be tested. "To estimate how many we will be able to collect is simply premature," he said. "It's possible that we would collect somewhere less than 200,000 and still have a very statistically valid sampling."
DeHaven said USDA veterinarians will work with state veterinarians and other state officials to develop plans for collecting cattle samples for testing in each state.
See also:
Transcript of USDA's Mar 15 news briefing http://www.usda.gov/Newsroom/0106.04.html
Robert Roos, CIDRAP News Editor, contributed to this story.
USDA did not test possible mad cows
By Steve Mitchell
United Press International
Published 6/8/2004 9:30 PM
WASHINGTON, June 8 (UPI) -- The U.S. Department of Agriculture claims it tested 500 cows with signs of a brain disorder for mad cow disease last year, but agency documents obtained by United Press International show the agency tested only half that number.
i almost forgot LOL;
BESIDES THE TEXAS MAD COW THAT WAS RENDERED AND NEVER TESTED;
On Friday, April 30 th , the Food and Drug Administration learned that a cow with central nervous system symptoms had been killed and shipped to a processor for rendering into animal protein for use in animal feed.
FDA, which is responsible for the safety of animal feed, immediately began an investigation. On Friday and throughout the weekend, FDA investigators inspected the slaughterhouse, the rendering facility, the farm where the animal came from, and the processor that initially received the cow from the slaughterhouse.
FDA's investigation showed that the animal in question had already been rendered into "meat and bone meal" (a type of protein animal feed). Over the weekend FDA was able to track down all the implicated material. That material is being held by the firm, which is cooperating fully with FDA. ...
http://www.fda.gov/bbs/topics/news/2004/NEW01061.html
USDA orders silence on mad cow in Texas
By Steve Mitchell United Press International Published 5/11/2004 10:16 PM
WASHINGTON, May 11 (UPI) -- The U.S. Department of Agriculture has issued an order instructing its inspectors in Texas, where federal madcow disease testing policies recently were violated, not to talk about the cattle disorder with outside parties, United Press International has learned.
The order, sent May 6 by e-mail from the USDA's Dallas district office,was issued in the wake of the April 27 case at Lone Star Beef in San Angelo, in which a cow displaying signs of a brain disorder was not tested for mad cow disease despite a federal policy to screen all such animals.
The deadly illness also is known as bovine spongiform encephalopathy.
Both the USDA and its Inspector General -- amid allegations that an offsite supervisor overruled the opinion of the inspectors on site and made the final decision not to test the animal -- have opened up investigations to determine why agency policy was violated.
The order, which was obtained by UPI, was issued by Ijaz Qazi, circuit supervisor for the USDA's Food Safety and Inspection Service's Dallas district, which covers the entire state. It reads: "All BSE inquiries MUST be directed to Congressional Public Affairs Phone 202-720-9113 attention Rob Larew OR Steve Khon. This is an urgent message. Any question contact me. Ijaz Qazi."
Although the language might sound innocuous, experienced inspectors familiar with USDA parlance have taken to referring to the notice as a "gag order."
The National Joint Council of Food Inspection Locals -- the national inspectors union -- considers the order a violation of inspectors' freespeech rights and is considering legal action against the USDA for breaching the labor agreement they have with the agency.
Inspectors alleged the order also suggests the agency is concerned about its personnel leaking damaging information about either the Texas case or the USDA's overall mad cow disease surveillance program, which has come under fire since the discovery of an infected cow in Washington state last December.
"Anytime the government suppresses an individual's freedom of speech,that's unconstitutional," Gary Dahl, president of Local 925, the Colorado inspectors union, told UPI.
Stanley Painter, chairman of the National Joint Council, said the USDA has sent out notices in the past stating inspectors cannot talk to reporters.
"It's an intimidation thing," Painter told UPI. Inspectors have the right to talk to anybody about any subject, as long as they clarify they are not speaking on behalf of the USDA and they are not doing it on government time, he said.
USDA spokesman Steven Cohen said he was not familiar with the notice from the Dallas office. He said he would look into it, but did not respond by UPI's publication time. In general, Cohen said, "There's an expectation any statement on behalf of the agency would come from the office of communications (in Washington.)"
Asked if employees could speak freely as long as they clarified that their views did not reflect those of the agency, Cohen said, "We'd rather that agency policy be communicated by those in a position to speak for the agency."
Qazi told UPI the notice was not issued in conjunction with the Texas case and it was routine agency practice that outside inquiries be referred to the Washington office. He said inspectors are free to talk to outside parties, including reporters, and he did not consider the e-mail a violation of the labor agreement with the inspectors.
Painter said the USDA's efforts to keep its employees from talking about mad cow would be better spent "with issues like protecting the consuming public instead of trying to hide things." He added he would "just about bet his last nickel" agency management was attempting to suppress information about the Texas case.
"To keep federal employees from reporting government waste, misuse ofappropriations -- those types of things -- that's not a good thing either," Dahl said. "If there is something wrong, let's get it out in the open -- let's get it fixed. We're working for the public, the American consumers. I think they have the right to know this," he said.
"And believe me there's so many indicators saying that the USDA's madcow testing program is broken," Dahl added.
At least one member of Congress, Sen. Tom Harkin, D-Iowa, agrees.
Harkin, a long-time critic of the USDA, sent a letter to Agriculture Secretary Ann Veneman on Monday, saying the Texas incident "calls into question the effectiveness and reliability of USDA's current and proposed surveillance system."
The USDA has proposed testing more than 200,000 cows -- or 10 times its current rate -- in an expanded program scheduled to begin June 1. Harkin wrote in the five-page letter, however, that given the realities of the cattle industry, it is "quite doubtful" the USDA will be able to test that many cows, particularly because it had difficulty finding 20,000 last year.
"We simply cannot tolerate a BSE testing system that fails to give valid answers to critical questions for U.S. consumers and foreign customers,"Harkin said in the letter, which sharply criticizes the agency's failure to address explicitly how its new surveillance program will be implemented.
"We look forward to receiving (Harkin's) letter and having the opportunity to review it and respond to him," USDA spokesman Ed Loyd told UPI. "USDA has acknowledged there was a failure in not testing that cow in Texas for BSE, so we are all working to ensure that does not occur again."
Jim Rogers, a spokesman for USDA's Animal and Plant Health InspectionService, which oversees the agency's mad cow surveillance program, told UPI the agency has tested about 15,500 animals since fiscal year 2004 began, on Oct. 1, 2003. However, the agency has refused to identify the states and facilities from which the cows originated. Rogers said UPI would have to seek that information through the Freedom of Information Act.
The question is central to the USDA's implementation of its expanded surveillance program. Downer cows -- those unable to stand or walk --made up the bulk of the animals the agency tested for mad cow inprevious years, but these were banned from being slaughtered for human consumption in December. This means the agency inspectors no longer can obtain brain samples from these cows at slaughterhouses as they could in the past.
Furthermore, the USDA has not provided any evidence it has worked out agreements with rendering facilities or ranchers, where downers and dead cows are now most likely to be found, to obtain the extra animals for testing.
Loyd said the agency is "working very hard to get animals on the farm that would never show up in a processing facility," and he was "not aware of any issues" that would delay the launch of the new program.
However, he was unable to provide the names or locations of the rendering facilities where the agency will be obtaining cow brains for BSE testing. He said he would look into it but did not return two follow-up phone calls from UPI before publication.
--
Steve Mitchell is UPI's Medical Correspondent. E-mail sciencemail@upi.com
Copyright © 2001-2004 United Press International
THE REST IS HISTORY, more atypical bse mad cow cases were showing up, testing questionable to say the least, i remind you of the infamous BSE ENHANCED and SUPRESSED BSE SURVEILLANCE AND THE HARVARD BSE BS that followed, and why the infamous ENHANCED BSE SURVEILLANCE AND TESTING WAS SHUT DOWN...terry
Audit Report Animal and Plant Health Inspection Service Bovine Spongiform Encephalopathy (BSE) Surveillance Program – Phase II
and
Food Safety and Inspection Service Controls Over BSE Sampling, Specified Risk Materials, and Advanced Meat Recovery Products - Phase III
"These 9,200 cases were different because brain tissue samples were preserved with formalin, which makes them suitable for only one type of test--immunohistochemistry, or IHC."
THIS WAS DONE FOR A REASON!
THE IHC test has been proven to be the LEAST LIKELY to detect BSE/TSE in the bovine, and these were probably from the most high risk cattle pool, the ones the USDA et al, SHOULD have been testing. ...TSS
TEXAS 2ND MAD COW THAT WAS COVERED UP, AFTER AN ACT OF CONGRESS, AND CALLS FROM TSE PRION SCIENTIST AROUND THE GLOBE, THIS 2ND MAD COW IN TEXAS WAS CONFIRMED
THE USDA MAD COW FOLLIES POSITIVE TEST COVER UP
JOHANNS SECRET POSTIVE MAD COW TEST THAT WERE IGNORED
OIG AND THE HONORABLE FONG CONFIRMS TEXAS MAD AFTER AN ACT OF CONGRESS 7 MONTHS LATER
TEXAS MAD COW
THEY DID FINALLY TEST AFTER SITTING 7+ MONTHS ON A SHELF WHILE GW BORE THE BSE MRR POLICY, i.e. legal trading of all strains of TSE. now understand, i confirmed this case 7 months earlier to the TAHC, and then, only after i contacted the Honorable Phyllis Fong and after an act of Congress, this animal was finally confirmed ;
During the course of the investigation, USDA removed and tested a total of 67 animals of interest from the farm where the index animal's herd originated. All of these animals tested negative for BSE. 200 adult animals of interest were determined to have left the index farm. Of these 200, APHIS officials determined that 143 had gone to slaughter, two were found alive (one was determined not to be of interest because of its age and the other tested negative), 34 are presumed dead, one is known dead and 20 have been classified as untraceable. In addition to the adult animals, APHIS was looking for two calves born to the index animal. Due to record keeping and identification issues, APHIS had to trace 213 calves. Of these 213 calves, 208 entered feeding and slaughter channels, four are presumed to have entered feeding and slaughter channels and one calf was untraceable.
see new link;
Executive Summary In June 2005, an inconclusive bovine spongiform encephalopathy (BSE) sample from November 2004, that had originally been classified as negative on the immunohistochemistry test, was confirmed positive on SAF immunoblot (Western blot). The U.S. Department of Agriculture (USDA) identified the herd of origin for the index cow in Texas; that identification was confirmed by DNA analysis. USDA, in close cooperation with the Texas Animal Health Commission (TAHC), established an incident command post (ICP) and began response activities according to USDA’s BSE Response Plan of September 2004. Response personnel removed at-risk cattle and cattle of interest (COI) from the index herd, euthanized them, and tested them for BSE; all were negative. USDA and the State extensively traced all at-risk cattle and COI that left the index herd. The majority of these animals entered rendering and/or slaughter channels well before the investigation began. USDA’s response to the Texas finding was thorough and effective.
snip...
Trace Herd 3 The owner of Trace Herd 3 was identified as possibly having received an animal of interest. The herd was placed under hold order on 7/27/05. The herd inventory was conducted on 7/28/05. The animal of interest was not present within the herd, and the hold order was released on 7/28/05. The person who thought he sold the animal to the owner of Trace Herd 3 had no records and could not remember who else he might have sold the cow to. Additionally, a search of GDB for all cattle sold through the markets by that individual did not result in a match to the animal of interest. The animal of interest traced to this herd was classified as untraceable because all leads were exhausted.
Trace Herd 4 The owner of Trace Herd 4 was identified as having received one of the COI through an order buyer. Trace Herd 4 was placed under hold order on 7/29/05. A complete herd inventory was conducted on 8/22/05 and 8/23/05. There were 233 head of cattle that were examined individually by both State and Federal personnel for all man-made identification and brands. The animal of interest was not present within the herd. Several animals were reported to have died in the herd sometime after they arrived on the premises in April 2005. A final search of GDB records yielded no further results on the eartag of interest at either subsequent market sale or slaughter. With all leads having been exhausted, this animal of interest has been classified as untraceable. The hold order on Trace Herd 4 was released on 8/23/05.
Trace Herd 5 The owner of Trace Herd 5 was identified as having received two COI and was placed under hold order on 8/1/05. Trace Herd 5 is made up of 67 head of cattle in multiple pastures. During the course of the herd inventory, the owner located records that indicated that one of the COI, a known birth cohort, had been sold to Trace Herd 8 where she was subsequently found alive. Upon completion of the herd inventory, the other animal of interest was not found within the herd. A GDB search of all recorded herd tests conducted on Trace Herd 5 and all market sales by the owner failed to locate the identification tag of the animal of interest and she was subsequently classified as untraceable due to all leads having been exhausted. The hold order on Trace Herd 5 was released on 8/8/05.
Trace Herd 6 The owner of Trace Herd 6 was identified as possibly having received an animal of interest and was placed under hold order on 8/1/05. This herd is made up of 58 head of cattle on two pastures. A herd inventory was conducted and the animal of interest was not present within the herd. The owner of Trace Herd 6 had very limited records and was unable to provide further information on where the cow might have gone after he purchased her from the livestock market. A search of GDB for all cattle sold through the markets by that individual did not result in a match to the animal of interest. Additionally, many of the animals presented for sale by the owner of the herd had been re-tagged at the market effectually losing the traceability of the history of that animal prior to re-tagging. The animal of interest traced to this herd was classified as untraceable due to all leads having been exhausted. The hold order on Trace Herd 6 was released on 8/3/05.
Trace Herd 7 The owner of Trace Herd 7 was identified as having received an animal of interest and was placed under hold order on 8/1/05. Trace Herd 7 contains 487 head of cattle on multiple pastures in multiple parts of the State, including a unit kept on an island. The island location is a particularly rough place to keep cattle and the owner claimed to have lost 22 head on the island in 2004 due to liver flukes. Upon completion of the herd inventory, the animal of interest was not found present within Trace Herd 7. A GDB search of all recorded herd tests conducted on Trace Herd 7 and all market sales by the owner failed to locate the identification tag of the animal of interest. The cow was subsequently classified as untraceable. It is quite possible though that she may have died within the herd, especially if she belonged to the island unit. The hold order on Trace Herd 7 was released on 8/8/05.
SEE;
Owner and Corporation Plead Guilty to Defrauding Bovine Spongiform Encephalopathy (BSE) Surveillance Program
An Arizona meat processing company and its owner pled guilty in February 2007 to charges of theft of Government funds, mail fraud, and wire fraud. The owner and his company defrauded the BSE Surveillance Program when they falsified BSE Surveillance Data Collection Forms and then submitted payment requests to USDA for the services. In addition to the targeted sample population (those cattle that were more than 30 months old or had other risk factors for BSE), the owner submitted to USDA, or caused to be submitted, BSE obex (brain stem) samples from healthy USDA-inspected cattle. As a result, the owner fraudulently received approximately $390,000. Sentencing is scheduled for May 2007.
snip...
4 USDA OIG SEMIANNUAL REPORT TO CONGRESS FY 2007 1st Half
SEE;
Audit Report Animal and Plant Health Inspection Service Bovine Spongiform Encephalopathy (BSE) Surveillance Program – Phase II and Food Safety and Inspection Service Controls Over BSE Sampling, Specified Risk Materials, and Advanced Meat Recovery Products - Phase III
UNITED STATES DEPARTMENT OF AGRICULTURE OFFICE OF INSPECTOR GENERAL Washington, D.C. 20250 January 25, 2006 REPLY TO ATTN OF: 50601-10-KC TO: W. Ron DeHaven Administrator Animal and Plant Health Inspection Service Barbara Masters Administrator Food Safety and Inspection Service ATTN: William J. Hudnall Deputy Administrator Marketing Regulatory Program Business Services William C. Smith Assistant Administrator Office of Program Evaluation, Enforcement, and Review FROM: Robert W. Young /s/ Assistant Inspector General for Audit SUBJECT: Animal and Plant Health Inspection Service - Bovine Spongiform Encephalopathy (BSE) Surveillance Program - Phase II and Food Safety and Inspection Service - Controls Over BSE Sampling, Specified Risk Materials, and Advanced Meat Recovery Products - Phase III This report presents the results of our audit of the enhanced BSE surveillance program and controls over specified risk materials and advanced meat recovery products. Your written response to the official draft report, dated January 20, 2006, is included as exhibit G with excerpts of the response and the Office of Inspector General’s (OIG) position incorporated into the Findings and Recommendations section of the report, where applicable. We accept the management decisions for all recommendations. Please follow your agency’s internal procedures in forwarding documentation for final action to the Office of the Chief Financial Officer (OCFO). We are providing a separate memorandum to the agencies and OCFO that provides specific information on the actions to be completed to achieve final action. We appreciate your timely response and the cooperation and assistance provided to our staff during the audit USDA/OIG-A/50601-10-KC/ Page i
Executive Summary
Animal and Plant Health Inspection Service - Bovine Spongiform Encephalopathy (BSE) Surveillance Program - Phase II and Food Safety and Inspection Service - Controls Over BSE Sampling, Specified Risk Materials, and Advanced Meat Recovery Products - Phase III
Results in Brief This report evaluates elements of the interlocking safeguards in place to protect United States (U.S.) beef from Bovine Spongiform Encephalopathy, widely known as BSE or "mad cow disease." Since 1990, the U.S. Department of Agriculture (USDA), Animal and Plant Health Inspection Service (APHIS), has led a multi-agency effort to monitor and prevent BSE from entering the food supply. After discovering a BSE-positive cow in December 2003, APHIS expanded its BSE surveillance program. To further protect the food supply, USDA banned materials identified as being at risk of carrying BSE (specified risk materials (SRM)), such as central nervous system tissue. As part of this effort, USDA’s Food Safety and Inspection Service (FSIS) required beef slaughter and processing facilities to incorporate controls for handling such materials into their operational plans. Onsite FSIS inspectors also inspect cattle for clinical signs in order to prevent diseased animals from being slaughtered for human consumption. To evaluate the effectiveness of the safeguards, we assessed APHIS’ implementation of the expanded surveillance program, as well as FSIS’ controls to prevent banned SRMs from entering the food supply.
In June 2004, APHIS implemented its expanded surveillance program; participation by industry in this surveillance program is voluntary. As of May 2005, over 350,000 animals were sampled and tested for BSE. To date, two animals tested positive for BSE; one tested positive after implementation of the expanded surveillance program.
USDA made significant efforts to implement the expanded BSE surveillance program. Much needed to be done in a short period of time to establish the necessary processes, controls, infrastructure, and networks to assist in this effort. In addition, extensive outreach and coordination was undertaken with other Federal, State, and local entities, private industry, and laboratory and veterinary networks. This report provides an assessment as to the progress USDA made in expanding its surveillance effort and the effectiveness of its controls and processes. This report also discusses the limitations of its program and data in assessing the prevalence of BSE in the U.S. herd.
snip...
40 ELISA test procedures require two additional (duplicate) tests if the initial test is reactive, before final interpretation. If either of the duplicate tests is reactive, the test is deemed inconclusive.
41 Protocol for BSE Contract Laboratories to Receive and Test Bovine Brain Samples and Report Results for BSE Surveillance Standard Operating Procedure (SOP), dated October 26, 2004.
42 The NVSL conducted an ELISA test on the original material tested at the contract laboratory and on two new cuts from the sample tissue.
43 A visual examination of brain tissue by a microscope.
44 A localized pathological change in a bodily organ or tissue.
SNIP...
PLEASE SEE FLAMING EVIDENCE THAT THE USDA ET AL COVERED UP MAD COW DISEASE IN TEXAS ;
PAGE 43;
Section 2. Testing Protocols and Quality Assurance Controls
snip...
FULL TEXT 130 PAGES
SEE;
Comments on technical aspects of the risk assessment were then submitted to FSIS.
Comments were received from Food and Water Watch, Food Animal Concerns Trust (FACT), Farm Sanctuary, R-CALF USA, Linda A Detwiler, and Terry S. Singeltary.
This document provides itemized replies to the public comments received on the 2005 updated Harvard BSE risk assessment. Please bear the following points in mind:
SEE;
Owens, Julie From: Terry S. Singeltary Sr. [flounder9@verizon.net]
Sent: Monday, July 24, 2006 1:09 PM To: FSIS RegulationsComments
Subject: [Docket No. FSIS-2006-0011] FSIS Harvard Risk Assessment of Bovine Spongiform Encephalopathy (BSE) Page 1 of 98 8/3/2006
Greetings FSIS, I would kindly like to comment on the following ;
SEE;
Suppressed peer review of Harvard study October 31, 2002.
October 31, 2002 Review of the Evaluation of the Potential for Bovine Spongiform Encephalopathy in the United States Conducted by the Harvard Center for Risk Analysis, Harvard School of Public Health and Center for Computational Epidemiology, College of Veterinary Medicine, Tuskegee University Final Report Prepared for U.S. Department of Agriculture Food Safety and Inspection Service Office of Public Health and Science Prepared by RTI Health, Social, and Economics Research Research Triangle Park, NC 27709 RTI Project Number 07182.024
SEE;
FULL TEXT OF GOA REPORT BELOW (takes a while to load)
2. Mad Cow Disease: Improvements in the Animal Feed Ban and Other Regulatory Areas Would Strengthen U.S. Prevention Efforts. GAO-02-183, January 25.
SATURDAY, AUGUST 16, 2008
Qualitative Analysis of BSE Risk Factors in the United States February 13, 2000 at 3:37 pm PST (BSE red book)
Tuesday, September 14, 2010
Transmissible Spongiform Encephalopathies Advisory Committee; Notice of Meeting October 28 and 29, 2010 (COMMENT SUBMISSION)
FULL TEXT OF GOA REPORT BELOW (takes a while to load)
2. Mad Cow Disease: Improvements in the Animal Feed Ban and Other Regulatory Areas Would Strengthen U.S. Prevention Efforts. GAO-02-183, January 25.
8 hr BSE confirmation turnaround took 7+ months to confirm this case, so the BSE MRR policy could be put into place. ...TSS
-------- Original Message --------
Subject: re-USDA's surveillance plan for BSE aka mad cow disease
Date: Mon, 02 May 2005 16:59:07 -0500
From: "Terry S. Singeltary Sr."
Greetings Honorable Paul Feeney, Keith Arnold, and William Busbyet al at OIG, ...............
snip...
There will be several more emails of my research to follow. I respectfully request a full inquiry into the cover-up of TSEs in the United States of America over the past 30 years. I would be happy to testify...
Thank you, I am sincerely, Terry S. Singeltary Sr. P.O. Box , Bacliff, Texas USA 77518 xxx xxx xxxx
Date: June 14, 2005 at 1:46 pm PST
In Reply to:
Re: Transcript Ag. Secretary Mike Johanns and Dr. John Clifford, Regarding further analysis of BSE Inconclusive Test Results
posted by TSS on June 13, 2005 at 7:33 pm:
Secretary of Agriculture Ann M. Veneman resigns Nov 15 2004, three days later inclusive Mad Cow is announced. June 7th 2005 Bill Hawks Under Secretary for Marketing and Regulatory Programs resigns. Three days later same mad cow found in November turns out to be positive. Both resignation are unexpected. just pondering... TSS
*** 2009 UPDATE ON ALABAMA AND TEXAS MAD COWS 2005 and 2006 ***
03-025IFA
03-025IFA-2
Terry S. Singeltary
From: Terry S. Singeltary Sr. [flounder9@verizon.net]
Sent: Thursday, September 08, 2005 6:17 PM
To: fsis.regulationscomments@fsis.usda.gov
Subject: [Docket No. 03-025IFA] FSIS Prohibition of the Use of Specified Risk Materials for Human Food and Requirements for the Disposition of Non-Ambulatory Disabled Cattle
PDF]Freas, William TSS SUBMISSION
File Format: PDF/Adobe Acrobat - Page 1. J Freas, William From: Sent: To: Subject: Terry S. Singeltary Sr. [flounder@wt.net] Monday, January 08,200l 3:03 PM freas ... http://web.archive.org/web/20170301223601/https://www.fda.gov/OHRMS/DOCKETS/AC/01/slides/3681s2_09.pdf
Sunday, January 10, 2021APHIS Concurrence With OIE Risk Designation for Bovine Spongiform Encephalopathy [Docket No. APHIS-2018-0087] Singeltary Submission June 17, 2019APHIS Concurrence With OIE Risk Designation for Bovine Spongiform Encephalopathy [Docket No. APHIS-2018-0087] Singeltary SubmissionGreetings APHIS et al,I would kindly like to comment on APHIS Concurrence With OIE Risk Designation for Bovine Spongiform Encephalopathy [Docket No. APHIS-2018-0087], and my comments are as follows, with the latest peer review and transmission studies as references of evidence.THE OIE/USDA BSE Minimal Risk Region MRR is nothing more than free pass to import and export the Transmissible Spongiform Encephalopathy TSE Prion disease. December 2003, when the USDA et al lost it's supposedly 'GOLD CARD' ie BSE FREE STATUS (that was based on nothing more than not looking and not finding BSE), once the USA lost it's gold card BSE Free status, the USDA OIE et al worked hard and fast to change the BSE Geographical Risk Statuses i.e. the BSE GBR's, and replaced it with the BSE MRR policy, the legal tool to trade mad cow type disease TSE Prion Globally. The USA is doing just what the UK did, when they shipped mad cow disease around the world, except with the BSE MRR policy, it's now legal.Also, the whole concept of the BSE MRR policy is based on a false pretense, that atypical BSE is not transmissible, and that only typical c-BSE is transmissible via feed. This notion that atypical BSE TSE Prion is an old age cow disease that is not infectious is absolutely false, there is NO science to show this, and on the contrary, we now know that atypical BSE will transmit by ORAL ROUTES, but even much more concerning now, recent science has shown that Chronic Wasting Disease CWD TSE Prion in deer and elk which is rampant with no stopping is sight in the USA, and Scrapie TSE Prion in sheep and goat, will transmit to PIGS by oral routes, this is our worst nightmare, showing even more risk factors for the USA FDA PART 589 TSE PRION FEED ban.The FDA PART 589 TSE PRION FEED ban has failed terribly bad, and is still failing, since August 1997. there is tonnage and tonnage of banned potential mad cow feed that went into commerce, and still is, with one decade, 10 YEARS, post August 1997 FDA PART 589 TSE PRION FEED ban, 2007, with 10,000,000 POUNDS, with REASON, Products manufactured from bulk feed containing blood meal that was cross contaminated with prohibited meat and bone meal and the labeling did not bear cautionary BSE statement. you can see all these feed ban warning letters and tonnage of mad cow feed in commerce, year after year, that is not accessible on the internet anymore like it use to be, you can see history of the FDA failure August 1997 FDA PART 589 TSE PRION FEED ban here, but remember this, we have a new outbreak of TSE Prion disease in a new livestock species, the camel, and this too is very worrisome.WITH the OIE and the USDA et al weakening the global TSE prion surveillance, by not classifying the atypical Scrapie as TSE Prion disease, and the notion that they want to do the same thing with typical scrapie and atypical BSE, it's just not scientific.WE MUST abolish the BSE MRR policy, go back to the BSE GBR risk assessments by country, and enhance them to include all strains of TSE Prion disease in all species. With Chronic Wasting CWD TSE Prion disease spreading in Europe, now including, Norway, Finland, Sweden, also in Korea, Canada and the USA, and the TSE Prion in Camels, the fact the the USA is feeding potentially CWD, Scrapie, BSE, typical and atypical, to other animals, and shipping both this feed and or live animals or even grains around the globe, potentially exposed or infected with the TSE Prion. this APHIS Concurrence With OIE Risk Designation for Bovine Spongiform Encephalopathy [Docket No. APHIS-2018-0087], under it's present definition, does NOT show the true risk of the TSE Prion in any country. as i said, it's nothing more than a legal tool to trade the TSE Prion around the globe, nothing but ink on paper.AS long as the BSE MRR policy stays in effect, TSE Prion disease will continued to be bought and sold as food for both humans and animals around the globe, and the future ramifications from friendly fire there from, i.e. iatrogenic exposure and transmission there from from all of the above, should not be underestimated. ...
APHIS Indemnity Regulations [Docket No. APHIS-2021-0010] RIN 0579-AE65 Singeltary Comment SubmissionComment from Singeltary Sr., TerryPosted by the Animal and Plant Health Inspection Service on Sep 8, 2022SO, WHO'S UP FOR SOME MORE TSE PRION POKER, WHO'S ALL IN $$$
SO, ATYPICAL SCRAPIE ROUGHLY HAS 50 50 CHANCE ATYPICAL SCRAPIE IS CONTAGIOUS, AS NON-CONTAGIOUS, TAKE YOUR PICK, BUT I SAID IT LONG AGO WHEN USDA OIE ET AL MADE ATYPICAL SCRAPIE A LEGAL TRADING COMMODITY, I SAID YOUR PUTTING THE CART BEFORE THE HORSE, AND THAT'S EXACTLY WHAT THEY DID, and it's called in Texas, TEXAS TSE PRION HOLDEM POKER, WHO'S ALL IN $$$
***> AS is considered more likely (subjective probability range 50–66%) that AS is a non-contagious, rather than a contagious, disease.
SNIP...SEE;
THURSDAY, JULY 8, 2021
EFSA Scientific report on the analysis of the 2‐year compulsory intensified monitoring of atypical scrapie
RE-Inactivation of porcine endogenous retrovirus in pigs using CPISPR-Cas9
TERRY S. SINGELTARY SR. - retired
- Mr.
seems that the USA feed ban for ruminant protein is still a serious problem, so there seems to still be a risk factor for pigs and Transmissible Spongiform Encephalopathy TSE prion disease. now with the updated science showing that pigs are susceptible to the Chronic Wasting Disease TSE Prion ORALLY, and cwd running rampant in the USA, any use of porcine organs should be tested for the CWD TSE Prion...
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Location: Virus and Prion Research
Title: Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease
Author item Moore, Sarah item Kunkle, Robert item Kondru, Naveen item Manne, Sireesha item Smith, Jodi item Kanthasamy, Anumantha item West Greenlee, M item Greenlee, Justin
Submitted to: Prion Publication Type: Abstract Only Publication Acceptance Date: 3/15/2017
Publication Date: N/A Citation: N/A Interpretive Summary:
Technical Abstract: Aims: Chronic wasting disease (CWD) is a naturally-occurring, fatal neurodegenerative disease of cervids. We previously demonstrated that disease-associated prion protein (PrPSc) can be detected in the brain and retina from pigs challenged intracranially or orally with the CWD agent. In that study, neurological signs consistent with prion disease were observed only in one pig: an intracranially challenged pig that was euthanized at 64 months post-challenge. The purpose of this study was to use an antigen-capture immunoassay (EIA) and real-time quaking-induced conversion (QuIC) to determine whether PrPSc is present in lymphoid tissues from pigs challenged with the CWD agent.
Methods: At two months of age, crossbred pigs were challenged by the intracranial route (n=20), oral route (n=19), or were left unchallenged (n=9). At approximately 6 months of age, the time at which commercial pigs reach market weight, half of the pigs in each group were culled (<6 month challenge groups). The remaining pigs (>6 month challenge groups) were allowed to incubate for up to 73 months post challenge (mpc). The retropharyngeal lymph node (RPLN) was screened for the presence of PrPSc by EIA and immunohistochemistry (IHC). The RPLN, palatine tonsil, and mesenteric lymph node (MLN) from 6-7 pigs per challenge group were also tested using EIA and QuIC.
Results: PrPSc was not detected by EIA and IHC in any RPLNs. All tonsils and MLNs were negative by IHC, though the MLN from one pig in the oral <6 month group was positive by EIA. PrPSc was detected by QuIC in at least one of the lymphoid tissues examined in 5/6 pigs in the intracranial <6 months group, 6/7 intracranial >6 months group, 5/6 pigs in the oral <6 months group, and 4/6 oral >6 months group. Overall, the MLN was positive in 14/19 (74%) of samples examined, the RPLN in 8/18 (44%), and the tonsil in 10/25 (40%). Conclusions:
This study demonstrates that PrPSc accumulates in lymphoid tissues from pigs challenged intracranially or orally with the CWD agent, and can be detected as early as 4 months after challenge.
CWD-infected pigs rarely develop clinical disease and if they do, they do so after a long incubation period. This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease.
Furthermore, lymphoid tissues from CWD-infected pigs could present a potential source of CWD infectivity in the animal and human food chains.
CONFIDENTIAL
EXPERIMENTAL PORCINE SPONGIFORM ENCEPHALOPATHY
While this clearly is a cause for concern we should not jump to the conclusion that this means that pigs will necessarily be infected by bone and meat meal fed by the oral route as is the case with cattle. ...
we cannot rule out the possibility that unrecognised subclinical spongiform encephalopathy could be present in British pigs though there is no evidence for this: only with parenteral/implantable pharmaceuticals/devices is the theoretical risk to humans of sufficient concern to consider any action.
Our records show that while some use is made of porcine materials in medicinal products, the only products which would appear to be in a hypothetically ''higher risk'' area are the adrenocorticotrophic hormone for which the source material comes from outside the United Kingdom, namely America China Sweden France and Germany. The products are manufactured by Ferring and Armour. A further product, ''Zenoderm Corium implant'' manufactured by Ethicon, makes use of porcine skin - which is not considered to be a ''high risk'' tissue, but one of its uses is described in the data sheet as ''in dural replacement''. This product is sourced from the United Kingdom.....
snip...see much more here ;
OIE Bulletin
Camel prion disease: a possible emerging disease in dromedary camel populations?
The identification of a new prion disease in dromedary camels in Algeria and Tunisia, called camel prion disease (CPD), extends the spectrum of animal species naturally susceptible to prion diseases and opens up new research areas for investigation.
Camel prion disease was identified in 2018 in adult camels showing clinical signs at the ante mortem inspection at slaughterhouses in the region of Ouargla (Algeria), and in 2019 in the region of Tataouine (Tunisia). It adds to the group of existing animal prion diseases, including scrapie in sheep and goats, chronic wasting disease (CWD) in cervids and BSE (mainly in bovines). The detection of a new prion disease in the dromedary population requires attention and investigation needs to be carried out to assess the risks of this disease to animal and public health. As of today, very limited epidemiological information is available to assess the prevalence, geographical distribution and dynamic of the transmission of the disease.
Based on the clinical signs suggesting prion disease, CPD seems to have occurred in 3.1% of the dromedaries brought to the abattoir in Ouargla. Pathognomonic neurodegeneration and disease specific prion protein (PrPSc) were detected in brain tissue from three symptomatic animals (source:
In May 2019, the OIE received a report from Tunisia on a single case of a 12-year-old slaughtered dromedary camel showing neurological signs confirmed as CPD by the Istituto Superiore di Sanità (ISS) based in Italy.
©B. Babelhadj/University Kasdi Merbah, Algeria
2
Is camel prion disease transmissible in natural conditions?
The involvement of lymphoid tissue in prion replication, observed both in the Algeria and Tunisia cases, is suggestive of a peripheral pathogenesis, which is thought to be a prerequisite for prion shedding into the environment. As with other animal prion diseases, such as scrapie and CWD, in which lymphoid tissues are extensively involved and horizontal transmission occurs efficiently under natural conditions, the detection of prion proteins in lymph nodes is suggestive of the infectious nature of CPD and concurs to hypothesise the potential impact of CPD on animal health. No evidence is currently available with which to argue for the relevance of CPD for human health. However, no absolute species barrier exists in prion diseases and minimising the exposure of humans to prion-infected animal products is an essential aspect of public health protection. As for the relationship between CPD and other animal prion diseases, preliminary analyses suggest that CPD prions have a different molecular signature from scrapie and BSE.
Actions on the follow up of CPD
Since the first description of CPD, the OIE promoted discussions on the impact of this new disease through the OIE Scientific Commission for Animal Diseases (Scientific Commission). The Scientific Commission consulted two OIE ad hoc Groups, one on BSE risk status evaluation of Members and the other on camelids. It analysed the information available from the Algeria and Tunisia cases to evaluate if CPD should be considered an ‘emerging disease’ based on the criteria listed in the Terrestrial Animal Health Code1 .
The OIE Scientific Commission noted that limited surveillance data were available on the prevalence of CPD and that the evidence was not sufficient to measure, at that time, the impact of the disease on animal or public health. Therefore, it was concluded that, with the current knowledge, CPD did not currently meet the criteria to be considered an emerging disease. Nonetheless, it was emphasised that CPD should be considered as a new disease not to be overlooked and called for the collection of further scientific evidence through research and surveillance in the affected countries and in countries with dromedary camel populations to measure the impact of the disease. As new scientific evidence becomes available, the OIE Scientific Commission will reassess whether this disease should be considered as an emerging disease.
The worldwide camel population is ~35 million head (FAO, 2019), 88% of which is found in Africa. The camel farming system is evolving rapidly, and these animals represent vital sources of meat, milk and transportation for millions of people living in the most arid regions of the world. This makes it necessary to assess the risk for animal and human health and to develop evidence-based policies to control and limit the spread of the disease in animals, and to minimise human exposure. As a first step, the awareness of Veterinary Services about CPD and its diagnostic capacity needs to be improved in all countries where dromedaries are part of the domestic livestock.
At the regional level, CPD was first discussed in the 18th Joint Permanent Committee of the Mediterranean Animal Health Network (REMESA) held in Cairo, Egypt, in June 2019 where an expert 1 a new occurrence in an animal of a disease, infection or infestation, causing a significant impact on animal or public health resulting from a) a change of a known pathogenic agent or its spread to a new geographic area or species, or b) a previously unrecognised pathogenic agent or disease diagnosed for the first time www.oiebulletin.com
3
from ISS, Italy, shared the knowledge available on the new disease with the 15 REMESA Member Countries. The discussion highlighted the need to strengthen surveillance systems in order to collect epidemiological data to inform the risk assessments. The results of these risk assessments will support the implementation of evidence-based policies to manage the risks in both animals and humans.
CPD was recently discussed atthe 15thConference of the OIE Regional Commission for the Middle East in November. During this conference, the CAMENET (Camel Middle East Network) launched a wide ranging proposal for training, coordinated surveillance and research on CPD. In addition, the ERFAN (Enhancing Research for Africa Network), a platform aimed at enhancing scientific cooperation between Africa and Italy, during its 2nd ERFAN meeting for North Africa, presented a project on CPD with the objective of increasing CPD coordinated surveillance in North Africa.
The OIE, through its Reference Laboratories for prion diseases, and by involving the above scientific initiatives, is keeping a close watch on the evolution of the disease to gather scientific evidence and to allow a proper and more thorough assessment of the risk associated with this novel disease.
◼ December 2019
Very low oral exposure to prions of brain or saliva origin can transmit chronic wasting disease
Nathaniel D. Denkers ,Clare E. Hoover ,Kristen A. Davenport,Davin M. Henderson,Erin E. McNulty,Amy V. Nalls,Candace K. Mathiason,Edward A. Hoover
Published: August 20, 2020
We report that oral exposure to as little as 300 nanograms (ng) of CWD-positive brain or to saliva containing seeding activity equivalent to 300 ng of CWD-positive brain, were sufficient to transmit CWD disease. This was true whether the inoculum was administered as a single bolus or divided as three weekly 100 ng exposures. However, when the 300 ng total dose was apportioned as 10, 30 ng doses delivered over 12 weeks, no infection occurred. While low-dose exposures to prions of brain or saliva origin prolonged the time from inoculation to first detection of infection, once infection was established, we observed no differences in disease pathogenesis. These studies suggest that the CWD minimum infectious dose approximates 100 to 300 ng CWD-positive brain (or saliva equivalent), and that CWD infection appears to conform more with a threshold than a cumulative dose dynamic.
WE know now, and we knew decades ago, that 5.5 grams of suspect feed in TEXAS was enough to kill 100 cows.
look at the table and you'll see that as little as 1 mg (or 0.001 gm) caused 7% (1 of 14) of the cows to come down with BSE;
Risk of oral infection with bovine spongiform encephalopathy agent in primates
Corinne Ida Lasmézas, Emmanuel Comoy, Stephen Hawkins, Christian Herzog, Franck Mouthon, Timm Konold, Frédéric Auvré, Evelyne Correia, Nathalie Lescoutra-Etchegaray, Nicole Salès, Gerald Wells, Paul Brown, Jean-Philippe Deslys
Summary The uncertain extent of human exposure to bovine spongiform encephalopathy (BSE)--which can lead to variant Creutzfeldt-Jakob disease (vCJD)--is compounded by incomplete knowledge about the efficiency of oral infection and the magnitude of any bovine-to-human biological barrier to transmission. We therefore investigated oral transmission of BSE to non-human primates. We gave two macaques a 5 g oral dose of brain homogenate from a BSE-infected cow. One macaque developed vCJD-like neurological disease 60 months after exposure, whereas the other remained free of disease at 76 months. On the basis of these findings and data from other studies, we made a preliminary estimate of the food exposure risk for man, which provides additional assurance that existing public health measures can prevent transmission of BSE to man.
snip...
BSE bovine brain inoculum
100 g 10 g 5 g 1 g 100 mg 10 mg 1 mg 0·1 mg 0·01 mg
Primate (oral route)* 1/2 (50%)
Cattle (oral route)* 10/10 (100%) 7/9 (78%) 7/10 (70%) 3/15 (20%) 1/15 (7%) 1/15 (7%)
RIII mice (ic ip route)* 17/18 (94%) 15/17 (88%) 1/14 (7%)
PrPres biochemical detection
The comparison is made on the basis of calibration of the bovine inoculum used in our study with primates against a bovine brain inoculum with a similar PrPres concentration that was inoculated into mice and cattle.8 *Data are number of animals positive/number of animals surviving at the time of clinical onset of disease in the first positive animal (%). The accuracy of bioassays is generally judged to be about plus or minus 1 log. ic ip=intracerebral and intraperitoneal.
Table 1: Comparison of transmission rates in primates and cattle infected orally with similar BSE brain inocula
Published online January 27, 2005
It is clear that the designing scientists must
also have shared Mr Bradley’s surprise at the results because all the dose
levels right down to 1 gram triggered infection.
6. It also appears to me that Mr Bradley’s answer (that it would take less than say 100
grams) was probably given with the benefit of hindsight; particularly if one
considers that later in the same answer Mr Bradley expresses his surprise that it
could take as little of 1 gram of brain to cause BSE by the oral route within the
same species. This information did not become available until the "attack rate"
experiment had been completed in 1995/96. This was a titration experiment
designed to ascertain the infective dose. A range of dosages was used to ensure
that the actual result was within both a lower and an upper limit within the study
and the designing scientists would not have expected all the dose levels to trigger
infection. The dose ranges chosen by the most informed scientists at that time
ranged from 1 gram to three times one hundred grams. It is clear that the designing
scientists must have also shared Mr Bradley’s surprise at the results because all the
dose levels right down to 1 gram triggered infection.
***> cattle, pigs, sheep, cwd, tse, prion, oh my!
***> In contrast, cattle are highly susceptible to white-tailed deer CWD and mule deer CWD in experimental conditions but no natural CWD infections in cattle have been reported (Sigurdson, 2008; Hamir et al., 2006).
Sheep and cattle may be exposed to CWD via common grazing areas with affected deer but so far, appear to be poorly susceptible to mule deer CWD (Sigurdson, 2008). In contrast, cattle are highly susceptible to white-tailed deer CWD and mule deer CWD in experimental conditions but no natural CWD infections in cattle have been reported (Sigurdson, 2008; Hamir et al., 2006). It is not known how susceptible humans are to CWD but given that the prion can be present in muscle, it is likely that humans have been exposed to the agent via consumption of venison (Sigurdson, 2008). Initial experimental research suggests that human susceptibility to CWD is low and there may be a robust species barrier for CWD transmission to humans (Sigurdson, 2008), however the risk appetite for a public health threat may still find this level unacceptable.
DEFRA
Friday, December 14, 2012
DEFRA U.K. What is the risk of Chronic Wasting Disease CWD being introduced into Great Britain? A Qualitative Risk Assessment October 2012
snip.....
In the USA, under the Food and Drug Administration's BSE Feed Regulation (21 CFR 589.2000) most material (exceptions include milk, tallow, and gelatin) from deer and elk is prohibited for use in feed for ruminant animals. With regards to feed for non-ruminant animals, under FDA law, CWD positive deer may not be used for any animal feed or feed ingredients. For elk and deer considered at high risk for CWD, the FDA recommends that these animals do not enter the animal feed system. However, this recommendation is guidance and not a requirement by law. Animals considered at high risk for CWD include:
1) animals from areas declared to be endemic for CWD and/or to be CWD eradication zones and
2) deer and elk that at some time during the 60-month period prior to slaughter were in a captive herd that contained a CWD-positive animal.
Therefore, in the USA, materials from cervids other than CWD positive animals may be used in animal feed and feed ingredients for non-ruminants.
The amount of animal PAP that is of deer and/or elk origin imported from the USA to GB can not be determined, however, as it is not specified in TRACES.
It may constitute a small percentage of the 8412 kilos of non-fish origin processed animal proteins that were imported from US into GB in 2011.
Overall, therefore, it is considered there is a __greater than negligible risk___ that (nonruminant) animal feed and pet food containing deer and/or elk protein is imported into GB.
There is uncertainty associated with this estimate given the lack of data on the amount of deer and/or elk protein possibly being imported in these products.
snip.....
36% in 2007 (Almberg et al., 2011). In such areas, population declines of deer of up to 30 to 50% have been observed (Almberg et al., 2011). In areas of Colorado, the prevalence can be as high as 30% (EFSA, 2011). The clinical signs of CWD in affected adults are weight loss and behavioural changes that can span weeks or months (Williams, 2005). In addition, signs might include excessive salivation, behavioural alterations including a fixed stare and changes in interaction with other animals in the herd, and an altered stance (Williams, 2005). These signs are indistinguishable from cervids experimentally infected with bovine spongiform encephalopathy (BSE). Given this, if CWD was to be introduced into countries with BSE such as GB, for example, infected deer populations would need to be tested to differentiate if they were infected with CWD or BSE to minimise the risk of BSE entering the human food-chain via affected venison. snip..... The rate of transmission of CWD has been reported to be as high as 30% and can approach 100% among captive animals in endemic areas (Safar et al., 2008).
snip.....
In summary, in endemic areas, there is a medium probability that the soil and surrounding environment is contaminated with CWD prions and in a bioavailable form. In rural areas where CWD has not been reported and deer are present, there is a greater than negligible risk the soil is contaminated with CWD prion. snip..... In summary, given the volume of tourists, hunters and servicemen moving between GB and North America, the probability of at least one person travelling to/from a CWD affected area and, in doing so, contaminating their clothing, footwear and/or equipment prior to arriving in GB is greater than negligible... For deer hunters, specifically, the risk is likely to be greater given the increased contact with deer and their environment. However, there is significant uncertainty associated with these estimates.
snip.....
Therefore, it is considered that farmed and park deer may have a higher probability of exposure to CWD transferred to the environment than wild deer given the restricted habitat range and higher frequency of contact with tourists and returning GB residents.
snip.....
a review of banned mad cow feed in USA;
BANNED MAD COW FEED IN COMMERCE IN ALABAMA
Date: September 6, 2006 at 7:58 am PST PRODUCT
a) EVSRC Custom dairy feed, Recall # V-130-6;
b) Performance Chick Starter, Recall # V-131-6;
c) Performance Quail Grower, Recall # V-132-6;
d) Performance Pheasant Finisher, Recall # V-133-6.
CODE None RECALLING FIRM/MANUFACTURER Donaldson & Hasenbein/dba J&R Feed Service, Inc., Cullman, AL, by telephone on June 23, 2006 and by letter dated July 19, 2006. Firm initiated recall is complete.
REASON
Dairy and poultry feeds were possibly contaminated with ruminant based protein.
VOLUME OF PRODUCT IN COMMERCE 477.72 tons
DISTRIBUTION AL
______________________________
http://www.fda.gov/bbs/topics/enforce/2006/ENF00968.html
SEE;
PRODUCT Bulk custom dairy pre-mixes,
Recall # V-120-6 CODE None RECALLING FIRM/MANUFACTURER Ware Milling Inc., Houston, MS, by telephone on June 23, 2006. Firm initiated recall is complete. REASON Possible contamination of dairy animal feeds with ruminant derived meat and bone meal.
VOLUME OF PRODUCT IN COMMERCE 350 tons
DISTRIBUTION AL and MS
______________________________
PRODUCT
a) Tucker Milling, LLC Tm 32% Sinking Fish Grower, #2680-Pellet, 50 lb. bags, Recall # V-121-6;
b) Tucker Milling, LLC #31120, Game Bird Breeder Pellet, 50 lb. bags, Recall # V-122-6;
c) Tucker Milling, LLC #31232 Game Bird Grower, 50 lb. bags, Recall # V-123-6;
d) Tucker Milling, LLC 31227-Crumble, Game Bird Starter, BMD Medicated, 50 lb bags, Recall # V-124-6;
e) Tucker Milling, LLC #31120, Game Bird Breeder, 50 lb bags, Recall # V-125-6;
f) Tucker Milling, LLC #30230, 30 % Turkey Starter, 50 lb bags, Recall # V-126-6;
g) Tucker Milling, LLC #30116, TM Broiler Finisher, 50 lb bags, Recall # V-127-6
CODE All products manufactured from 02/01/2005 until 06/20/2006 RECALLING FIRM/MANUFACTURER Recalling Firm: Tucker Milling LLC, Guntersville, AL, by telephone and visit on June 20, 2006, and by letter on June 23, 2006. Manufacturer: H. J. Baker and Brothers Inc., Stamford, CT. Firm initiated recall is ongoing.
REASON Poultry and fish feeds which were possibly contaminated with ruminant based protein were not labeled as "Do not feed to ruminants".
VOLUME OF PRODUCT IN COMMERCE 7,541-50 lb bags
DISTRIBUTION AL, GA, MS, and TN
END OF ENFORCEMENT REPORT FOR AUGUST 9, 2006
###
http://www.fda.gov/bbs/topics/ENFORCE/2006/ENF00964.html
Subject: MAD COW FEED RECALL AL AND FL VOLUME OF PRODUCT IN COMMERCE 125 TONS Products manufactured from 02/01/2005 until 06/06/2006
Date: August 6, 2006 at 6:16 pm PST PRODUCT
a) CO-OP 32% Sinking Catfish, Recall # V-100-6;
b) Performance Sheep Pell W/Decox/A/N, medicated, net wt. 50 lbs, Recall # V-101-6;
c) Pro 40% Swine Conc Meal -- 50 lb, Recall # V-102-6;
d) CO-OP 32% Sinking Catfish Food Medicated, Recall # V-103-6;
e) "Big Jim's" BBB Deer Ration, Big Buck Blend, Recall # V-104-6;
f) CO-OP 40% Hog Supplement Medicated Pelleted, Tylosin 100 grams/ton, 50 lb. bag, Recall # V-105-6;
g) Pig Starter Pell II, 18% W/MCDX Medicated 282020, Carbadox -- 0.0055%, Recall # V-106-6;
h) CO-OP STARTER-GROWER CRUMBLES, Complete Feed for Chickens from Hatch to 20 Weeks, Medicated, Bacitracin Methylene Disalicylate, 25 and 50 Lbs, Recall # V-107-6;
i) CO-OP LAYING PELLETS, Complete Feed for Laying Chickens, Recall # 108-6;
j) CO-OP LAYING CRUMBLES, Recall # V-109-6;
k) CO-OP QUAIL FLIGHT CONDITIONER MEDICATED, net wt 50 Lbs, Recall # V-110-6;
l) CO-OP QUAIL STARTER MEDICATED, Net Wt. 50 Lbs, Recall # V-111-6;
m) CO-OP QUAIL GROWER MEDICATED, 50 Lbs, Recall # V-112-6 CODE
Product manufactured from 02/01/2005 until 06/06/2006
RECALLING FIRM/MANUFACTURER Alabama Farmers Cooperative, Inc., Decatur, AL, by telephone, fax, email and visit on June 9, 2006. FDA initiated recall is complete.
REASON Animal and fish feeds which were possibly contaminated with ruminant based protein not labeled as "Do not feed to ruminants".
VOLUME OF PRODUCT IN COMMERCE 125 tons
DISTRIBUTION AL and FL
END OF ENFORCEMENT REPORT FOR AUGUST 2, 2006
###
http://www.fda.gov/bbs/topics/enforce/2006/ENF00963.html
MAD COW FEED RECALL USA EQUALS 10,878.06 TONS NATIONWIDE Sun Jul 16, 2006 09:22 71.248.128.67
RECALLS AND FIELD CORRECTIONS: VETERINARY MEDICINE -- CLASS II
______________________________
PRODUCT
a) PRO-LAK, bulk weight, Protein Concentrate for Lactating Dairy Animals, Recall # V-079-6;
b) ProAmino II, FOR PREFRESH AND LACTATING COWS, net weight 50lb (22.6 kg), Recall # V-080-6;
c) PRO-PAK, MARINE & ANIMAL PROTEIN CONCENTRATE FOR USE IN ANIMAL FEED, Recall # V-081-6;
d) Feather Meal, Recall # V-082-6 CODE
a) Bulk
b) None
c) Bulk
d) Bulk
RECALLING FIRM/MANUFACTURER H. J. Baker & Bro., Inc., Albertville, AL, by telephone on June 15, 2006 and by press release on June 16, 2006. Firm initiated recall is ongoing.
REASON
Possible contamination of animal feeds with ruminent derived meat and bone meal.
VOLUME OF PRODUCT IN COMMERCE 10,878.06 tons
DISTRIBUTION Nationwide
END OF ENFORCEMENT REPORT FOR July 12, 2006
###
http://www.fda.gov/bbs/topics/enforce/2006/ENF00960.html
10,000,000+ LBS. of PROHIBITED BANNED MAD COW FEED I.E. BLOOD LACED MBM IN COMMERCE USA 2007
Date: March 21, 2007 at 2:27 pm PST
RECALLS AND FIELD CORRECTIONS: VETERINARY MEDICINES -- CLASS II
___________________________________
PRODUCT
Bulk cattle feed made with recalled Darling's 85% Blood Meal, Flash Dried, Recall # V-024-2007
CODE
Cattle feed delivered between 01/12/2007 and 01/26/2007
RECALLING FIRM/MANUFACTURER
Pfeiffer, Arno, Inc, Greenbush, WI. by conversation on February 5, 2007.
Firm initiated recall is ongoing.
REASON
Blood meal used to make cattle feed was recalled because it was cross- contaminated with prohibited bovine meat and bone meal that had been manufactured on common equipment and labeling did not bear cautionary BSE statement.
VOLUME OF PRODUCT IN COMMERCE
42,090 lbs.
DISTRIBUTION
WI
___________________________________
PRODUCT
Custom dairy premix products: MNM ALL PURPOSE Pellet, HILLSIDE/CDL Prot- Buffer Meal, LEE, M.-CLOSE UP PX Pellet, HIGH DESERT/ GHC LACT Meal, TATARKA, M CUST PROT Meal, SUNRIDGE/CDL PROTEIN Blend, LOURENZO, K PVM DAIRY Meal, DOUBLE B DAIRY/GHC LAC Mineral, WEST PIONT/GHC CLOSEUP Mineral, WEST POINT/GHC LACT Meal, JENKS, J/COMPASS PROTEIN Meal, COPPINI - 8# SPECIAL DAIRY Mix, GULICK, L-LACT Meal (Bulk), TRIPLE J - PROTEIN/LACTATION, ROCK CREEK/GHC MILK Mineral, BETTENCOURT/GHC S.SIDE MK-MN, BETTENCOURT #1/GHC MILK MINR, V&C DAIRY/GHC LACT Meal, VEENSTRA, F/GHC LACT Meal, SMUTNY, A- BYPASS ML W/SMARTA, Recall # V-025-2007
CODE
The firm does not utilize a code - only shipping documentation with commodity and weights identified.
RECALLING FIRM/MANUFACTURER
Rangen, Inc, Buhl, ID, by letters on February 13 and 14, 2007. Firm initiated recall is complete.
REASON
Products manufactured from bulk feed containing blood meal that was cross contaminated with prohibited meat and bone meal and the labeling did not bear cautionary BSE statement.
VOLUME OF PRODUCT IN COMMERCE
9,997,976 lbs.
DISTRIBUTION
ID and NV
END OF ENFORCEMENT REPORT FOR MARCH 21, 2007
http://www.fda.gov/Safety/Recalls/EnforcementReports/2007/ucm120446.htm
MONDAY, OCTOBER 10, 2022
Docket No: 2002N-0273 (formerly Docket No. 02N-0273) Substances Prohibited From Use in Animal Food and Feed Scientists Comments December 20, 2005
This information is critical, and should continue to be collected.
The TSE prion is spreading across the USA in Cervid as in CWD TSE Prion.
The mad cow surveillance, feed ban, testing, and SRM removal there from, has been, and still is, a terrible failure.
WE know that the USA Food and Drug Administration's BSE Feed Regulation (21 CFR 589.2000) of August 1997 was/is a colossal failure, and proven to be so year after year, decade after decade, and this was just admitted by the FDA et al (see below FDA Reports on VFD Compliance Sept. 2019 report).
God, all these decades you hear from all the warning letters on SRM that were released to the public for consumption, that even if they did eat a SRM, the BSE Feed Regulation (21 CFR 589.2000) of August 1997 would save that tissue from that animal from having a TSE Prion, was nothing but lies. what about those children all across the USA that were fed the most high risk cattle for mad cow disease, i.e. dead stock downer cows via the USDA School lunch program, who will watch those kids for the next 50 years for cjd tse prion aka mad cow disease, let alone all the folks consuming SRMs that have been exposed to mad cow type disease in different livestock species, due to the fact the USA colossal failure of the BSE Feed Regulation (21 CFR 589.2000) of August 1997. it's all documented below, see for yourself; SUNDAY, SEPTEMBER 1, 2019 FDA Reports on VFD Compliance
Tuesday, September 10, 2019
FSIS [Docket No. FSIS–2019–0021] Notice of Request To Renew an Approved Information Collection: Specified Risk Materials Singeltary Submission
-------- Original Message --------
Subject: re-BSE prions propagate as either variant CJD-like or sporadic CJD
Date: Thu, 28 Nov 2002 10:23:43 -0000
From: "Asante, Emmanuel A" e.asante@ic.ac.uk
To: "'flounder@wt.net'" flounder@wt.net
Dear Terry,
I have been asked by Professor Collinge to respond to your request. I am a Senior Scientist in the MRC Prion Unit and the lead author on the paper. I have attached a pdf copy of the paper for your attention.
Thank you for your interest in the paper.
In respect of your first question, the simple answer is, ***yes. As you will find in the paper, we have managed to associate the alternate phenotype to type 2 PrPSc, the commonest sporadic CJD. It is too early to be able to claim any further sub-classification in respect of Heidenhain variant CJD or Vicky Rimmer's version. It will take further studies, which are on-going, to establish if there are sub-types to our initial finding which we are now reporting. The main point of the paper is that, as well as leading to the expected new variant CJD phenotype, BSE transmission to the 129-methionine genotype can lead to an alternate phenotype which is indistinguishable from type 2 PrPSc.
I hope reading the paper will enlighten you more on the subject. If I can be of any further assistance please to not hesitate to ask. Best wishes.
Emmanuel Asante
<<Asante et al 2002.pdf>>
____________________________________
Dr. Emmanuel A Asante MRC Prion Unit & Neurogenetics Dept. Imperial College School of Medicine (St. Mary's) Norfolk Place, LONDON W2 1PG Tel: +44 (0)20 7594 3794 Fax: +44 (0)20 7706 3272 email: e.asante@ic.ac.uk (until 9/12/02) New e-mail: e.asante@prion.ucl.ac.uk (active from now)
____________________________________
''This study demonstrates that the H-type BSE agent is transmissible by the oronasal route. Cattle with the EK211 genotype are oronasally susceptible to small doses of the H-BSE agent from either EK211 or EE211 (wild type) donors. Wild-type EE211 cattle remained asymptomatic for the duration of the experiment with this small dose (0.1g) of inoculum. These results reinforce the need for ongoing surveillance for classical and atypical BSE to minimize the risk of potentially infectious tissues entering the animal or human food chains.''
***Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.***
Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
PRION CONFERENCE 2022 ABSTRACTS CWD TSE PrP ZOONOSIS
Transmission of prion infectivity from CWD-infected macaque tissues to rodent models demonstrates the zoonotic potential of chronic wasting disease.
Samia Hannaouia, Ginny Chenga, Wiebke Wemheuerb, Walter J. Schulz-Schaefferb, Sabine Gilcha, and Hermann M. Schätzla aDepartment of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine & Hotchkiss Brain Institute; University of Calgary, Calgary, Canada; bInstitute of Neuropathology, Medical Faculty, Saarland University, Homburg/Saar, Germany
Aims: Chronic wasting disease (CWD) is a prion disease of cervids. Its rapid geographic expansion, shedding of infectivity and persistence in the environment for many years are of concern for humans. Here, we provide the first evidence by transmission experiments to different transgenic mouse models and bank voles that Cynomolgus macaques inoculated via different routes with CWD-positive cervid tissues harbor infectious prions that elicit clinical disease in rodents.
Material and Methods: We used tissue materials from macaques inoculated with CWD to inoculate transgenic mice overexpressing cervid PrPCfollowed by transmission into bank voles. We used RT-QuIC, immunoblot and PET blot analysis to assess brains, spinal cords, and tissues of the gastrointestinal tract (GIT) for the presence of prions.
Results: Our results show that of the macaque materials that induced clinical disease in transgenic mice,73% were from the CNS (46% spinal cord and 27% brain), and 27% were from the spleen, although attack rates were low around 20%. Clinical mice did not display PK-resistant PrPSc(PrPres) in immunoblot, but showed low-levels of prion seeding activity. Transmission into bank voles from clinical transgenic mice led to a 100% attack rate with typical PrPressignature in immunoblot, which was different from that of voles inoculated directly with CWD or scrapie prions. High-level prion seeding activity in brain and spinal cord and PrPresdeposition in the brain were present. Remarkably, we also found prion seeding activity in GIT tissues of inoculated voles. Second passage in bank voles led to a 100% attack rate in voles inoculated with brain, spinal cord and small intestine material from first round animals, with PrPresin immunoblot, prion seeding activity, and PrPresdeposition in the brain. Shortened survival times indicate adaptation in the new host. This also shows that prions detected in GIT tissues are infectious and transmissible. Transmission of brain material from sick voles back to cervidized mice revealed transmission in these mice with a 100% attack rate, and interestingly, with different biochemical signature and distribution in the brain.
Conclusions: Our findings demonstrate that macaques, considered the best model for the zoonotic potential of prions, were infected upon CWD challenge, including oral one. The disease manifested as atypical in macaques and transgenic mice, but with infectivity present at all times, as unveiled in the bank vole model with an unusual tissue tropism.
Funded by: The National Institutes of Health, USA, and the Alberta Prion Research Institute/Alberta Innovates Canada. Grant number: 1R01NS121016-01; 201,600,023
Acknowledgement: We thank Umberto Agrimi, Istituto Superiore di Sanità, Rome, Italy, and Michael Beekes, Robert-Koch Institute Berlin, Germany, for providing the bank vole model. We thank the University of Calgary animal facility staff and Dr. Stephanie Anderson for animal care.
Transmission of Cervid Prions to Humanized Mice Demonstrates the Zoonotic Potential of CWD
Samia Hannaouia, Irina Zemlyankinaa, Sheng Chun Changa, Maria Immaculata Arifina, Vincent Béringueb, Debbie McKenziec, Hermann M. Schatzla, and Sabine Gilcha
aDepartment of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine; Hotchkiss Brain Institute; University of Calgary, Calgary, Canada; bUniversité Paris-Saclay, INRAE, UVSQ, VIM, Jouy-en-Josas, France; cDepartment of Biological Sciences, Center for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Canada
Aims: Chronic wasting disease (CWD), a prion disease of cervids, spreads efficiently among wild and farmed animals. Potential transmission to humans of CWD is a growing concern due to its increasing prevalence. Here, we aimed to determine the zoonotic potential of CWD using a mouse model for human prion diseases.
Material and Methods: Transgenic mice overexpressing human PrPChomozygous for methionine at codon 129 (tg650) were inoculated intracerebrally with brain homogenates of white-tailed deer infected with Wisc-1/CWD1 or 116AG CWD strains. Mice were monitored for clinical signs and were euthanized at terminal disease. Brains were tested by RT-QuIC, western blot upon PK digestion, and immunohistochemistry; fecal homogenates were analyzed by RT-QuIC. Brain/spinal cord and fecal homogenates of CWD-inoculated tg650 mice were inoculated into tg650 mice or bank voles. Brain homogenates of bank voles inoculated with fecal homogenates of CWD-infected tg650 mice were used for second passage in bank voles.
Results: Here, we provide the strongest evidence supporting the zoonotic potential of CWD prions, and their possible phenotype in humans. Inoculation of mice expressing human PrPCwith deer CWD isolates (strains Wisc-1 and 116AG) resulted in atypical clinical manifestations in > 75% of the mice, with myoclonus as leading clinical sign. Most of tg650 brain homogenates were positive for seeding activity in RT-QuIC. Clinical disease and presentation was transmissible to tg650 mice and bank voles. Intriguingly, protease-resistant PrP in the brain of tg650 mice resembled that found in a familial human prion disease and was transmissible upon passage. Abnormal PrP aggregates upon infection with Wisc-1 were detectable in thalamus, hypothalamus, and midbrain/pons regions.
Unprecedented in human prion disease, feces of CWD-inoculated tg650 mice harbored prion seeding activity and infectious prions, as shown by inoculation of bank voles and tg650 with fecal homogenates.
Conclusions: This is the first evidence that CWD can infect humans and cause disease with a distinctive clinical presentation, signature, and tropism, which might be transmissible between humans while current diagnostic assays might fail to detect it. These findings have major implications for public health and CWD-management.
Funded by: We are grateful for financial support from the Natural Sciences and Engineering Research Council of Canada, the National Institutes of Health, Genome Canada, and the Alberta Prion Research Institute. SG is supported by the Canada Research Chairs program.
Acknowledgement: We thank Dr. Trent Bollinger, WCVM, University of Saskatchewan, Saskatoon, Canada, for providing brain tissue from the WTD-116AG isolate, Dr. Stéphane Haïk, ICM, Paris, France, for providing brain tissue from vCJD and sCJD cases, and Dr. Umberto Agrimi, Istituto Superiore di Sanità, Italy, for the bank vole model. We thank animal facility staff for animal care, Dr. Stephanie Anderson for veterinary oversight, and Yo-Ching Cheng for preparing recombinant PrP substrates. Thank you to Dr. Stephanie Booth and Jennifer Myskiw, Public Health Agency of Canada, Canada.
The chronic wasting disease agent from white-tailed deer is infectious to humanized mice after passage through raccoons
Eric Cassmanna, Xu Qib, Qingzhong Kongb, and Justin Greenleea
aNational Animal Disease Center, Agricultural Research Service, US Department of Agriculture, Ames, IA, USA bDepartments of Pathology, Neurology, National Center for Regenerative Medicine, and National Prion Disease Pathology Surveillance Center, Case Western Reserve University, Cleveland, Ohio, USA
Aims: Evaluate the zoonotic potential of the raccoon passaged chronic wasting disease (CWD) agent in humanized transgenic mice in comparison with the North American CWD agent from the original white-tailed deer host.
Material and Methods: Pooled brain material (GG96) from a CWD positive herd was used to oronasally inoculate two white-tailed deer with wild-type prion protein genotype and intracranially inoculate a raccoon. Brain homogenates (10% w/v) from the raccoon and the two white-tailed deer were used to intracranially inoculate separate groups of transgenic mice that express human prion protein with methionine (M) at codon 129 (Tg40h). Brains and spleens were collected from mice at experimental endpoints of clinical disease or approximately 700 days post-inoculation. Tissues were divided and homogenized or fixed in 10% buffered neutral formalin. Immunohistochemistry, enzyme immunoassay, and western blot were used to detect misfolded prion protein (PrPSc) in tissue.
Results: Humanized transgenic mice inoculated with the raccoon passaged CWD agent from white-tailed deer exhibited a 100% (12/12) attack rate with an average incubation period of 605 days. PrPScwas detected in brain tissue by enzyme immunoassay with an average optical density of 3.6/4.0 for positive brains. PrPScalso was detected in brain tissue by western blot and immunohistochemistry. No PrPScwas detected in the spleens of mice inoculated with the raccoon passaged CWD agent. Humanized mice inoculated with the CWD agent from white-tailed deer did not have detectable PrPScusing conventional immunoassay techniques.
Conclusions: The host range of the CWD agent from white-tailed deer was expanded in our experimental model after one passage through raccoons.
Funded by: This research was funded in its entirety by congressionally appropriated funds to the United States Department of Agriculture, Agricultural Research Service. The funders of the work did not influence study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Acknowledgement: We thank Quazetta Brown, Lexi Frese, Rylie Frese, Kevin Hassall, Leisa Mandell, and Trudy Tatum for providing excellent technical support to this project.
Stable and highly zoonotic cervid prion strain is possible
Manuel Camacho, Xu Qi, Liuting Qing, Sydney Smith, Jieji Hu, Wanyun Tao, Ignazio Cali, and Qingzhong Kong Department of Pathology, Case Western Reserve University, Cleveland, USA
Aims: Whether CWD prions can infect humans remains unclear despite the very substantial scale and long history of human exposure of CWD in some areas. Multiple in vitro conversion experiments and in vivo animal studies suggest that the CWD-to-human transmission barrier is not unbreakable. A major public health concern on CWD zoonosis is the emergence of highly zoonotic CWD strains. We aim to address the question of whether highly zoonotic CWD strains are possible.
Material and Methods: We inoculated a few sCJD brain samples into cervidized transgenic mice, which were intended as negative controls for bioassays of brain tissues from sCJD cases who had hunted or consumed vension from CWD-endemic states. Some of these mice became infected and their brain tissues were further examined by serial passages in humanized or cervidized mice.
Results: Passage of sCJDMM1 in transgenic mice expressing elk PrP (Tg12) resulted in a ‘cervidized’ CJD strain that we termed CJDElkPrP. We observed 100% transmission of CJDElkPrPin transgenic mice expressing human PrP (Tg40h). We passaged CJDElkPrPtwo more times in the Tg12 mice. We found that such second and third passage CJDElkPrPprions also led to 100% infection in the Tg40h mice. In contrast, we and others found zero or poor transmission of natural elk CWD isolates in humanized mice, despite that natural elk CWD isolates and CJDElkPrPshare the same elk PrP sequence.
Conclusions: Our data demonstrate that highly zoonotic cervid prion strains are not only possible but also can be stably maintained in cervids and that CWD zoonosis is prion strain-dependent.
Funded by: NIH
Grant number: R01NS052319, R01NS088604, R01NS109532
Acknowledgement: We want to thank the National Prion Disease Pathology Surveillance Center and Drs. Allen Jenny and Katherine O’Rourke for providing the sCJD samples and the CWD samples, respectively.
Adaptation of chronic wasting disease (CWD) prion strains in hosts with different PRNP genotypes
Camilo Duque Velasqueza,c, Elizabeth Triscotta,c, Chiye Kima,c, Diana Morenoa,c, Judd Aikenb,c, and Debbie McKenziea,c
aDepartment of Biological Science, University of Alberta, Edmonton, AB T6G 2G8, Canada; bDepartment of Agriculture, Food & Nutritional Science, University of Alberta, Edmonton, AB T6G 2G8, Canada; cCentre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB T6G 2M8, Canada
Aims: The contagious nature of CWD epizootics and the PrPCamino acid variation of cervids (and susceptible sympatric species) guarantee the expansion of prion conformational diversity and selective landscapes where new strains can arise. CWD strains can have novel transmission properties including altered host range that may increase zoonotic risk as circulating strains diversify and evolve. We are characterizing the host adaptability of characterized CWD strains as well as CWD isolates from different cervid species in various enzootic regions.
Material and Methods: Characterized CWD strains as well as a number of isolates from hunter-harvested deer were bioassayed in our rodent panel (transgenic mice expressing cervid alleles G96, S96 and H95-PrPC, elk PrPC, bovine PrPC, and both hamsters and non-transgenic laboratory mice). Strain characteristics were compared using computer based scoring of brain pathology (e.g. PrPCWDbrain distribution), western blot and protein misfolding cyclic amplification (PMCA).
Results: Transmission of various isolates resulted in the selection of strain mixtures in hosts expressing similar PrPC, particularly for polymorphic white-tailed deer and for Norwegian reindeer. As of the second passage, transmission of P153 moose prions from Norway has not resulted in emergence of strains with properties similar to any North American CWD strains in our taxonomic collection (Wisc-1, CWD2, H95+and 116AG).
Conclusions: Our data indicates polymorphic white-tailed deer can favor infection with more than one strain. Similar to transmission studies of Colorado CWD isolates from cervids expressing a single PrPCprimary structure, the isolate from Norway reindeer (V214) represents a strain mixture, suggesting intrinsic strain diversity in the Nordfjella epizootic. The diversity of CWD strains with distinct transmission characteristics represents a threat to wildlife, sympatric domestic animals and public health.
Funded by: Genome Canada and Genome Alberta (Alberta Prion Research Institute and Alberta Agriculture & Forestry); NSERC Grant number: #LSARP 10205; NSERC RGPIN-2017-05539
Acknowledgement: We would like to thank Margo Pybus (Alberta Environment and Parks) Trent Bollinger (University of Saskatchewan) for providing us with tissue samples from hunter-harvested deer and Sylvie Benestad for providing moose and reindeer samples.
Application of PMCA to understand CWD prion strains, species barrier and zoonotic potential
Sandra Pritzkowa, Damian Gorskia, Frank Ramireza, Fei Wanga, Glenn C. Tellingb, Justin J. Greenleec, Sylvie L. Benestadd, and Claudio Sotoa aDepartment of Neurology, University of Texas Medical School at Houston, Houston, Texas, USA; bDepartment of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA; cVirus and Prion Research Unit, United States Department of Agriculture, Ames, Iowa, USA; dNorwegian Veterinary Institute, OIE Reference Laboratory for CWD, Ås, Norway
Aims: Chronic wasting disease (CWD) is a prion disease affecting various species of cervids that continues to spread uncontrollably across North America and has recently been detected in Scandinavia (Norway, Sweden and Finland). The mechanisms responsible for the natural transmission of CWD are largely unknown. Furthermore, the risk of CWD transmission to other species, including humans, is also unknown and remains a dangerous enigma. In this study, we investigated the potential of CWD prions to infect several other animal species (sheep, cattle, pig, hamster, and mouse) including humans, by examining their capacity to convert the normal prion protein of distinct species in a PMCA reaction. Moreover, we also investigated whether the in vivo passage of CWD through intermediate species alters their capacity for zoonotic transmission, which may represent a major hazard to human health.
Material and Methods: For these studies, we used brain material from CWD-infected white-tailed deer (Odocoileus virginianus), elk (Cervus canadensis), and mule deer (Odocoileus hemionus) as species native to North America. We also used CWD-infected Moose (Alces alces), reindeer (Rangifer tarandus) and red deer (Cervus elaphus) as Norwegian cervids. We also used brains from cattle, sheep and pigs experimentally infected by CWD. To study interspecies-transmission and zoonotic potential, samples were tested via PMCA for the conversion of PrPCinto PrPScusing different combinations of inoculum and host species. Based on these analyses we estimated the spillover and zoonotic potential for different CWD isolates. We define and quantify spillover and zoonotic potential indices as the efficiency by which CWD prions sustain prion generation in vitro at the expense of normal prion proteins from various mammals and human, respectively.
Results: Our results show that prions from some cervid species, especially those found in Northern Europe, have a higher potential to transmit disease characteristics to other animals. Conversely, CWD-infected cervids originated in North America appear to have a greater potential to generate human PrPSc. We also found that in vivo transmission of CWD to cattle, but not to sheep or pigs substantially increases the ability of these prions to convert human PrPCby PMCA.
Conclusions: Our findings support the existence of different CWD prion strains with distinct spillover and zoonotic potentials. We also conclude that transmission of CWD to other animal species may increase the risk for CWD transmission to humans. Our studies may provide a tool to predict the array of animal species that a given CWD prion could affect and may contribute to understanding the risk of CWD for human health.
Funded by: National Institute of Health Grant number: P01 AI077774
Generation of human chronic wasting disease in transgenic mice
Zerui Wanga, Kefeng Qinb, Manuel V. Camachoa, Ignazio Cali a,c, Jue Yuana, Pingping Shena, Tricia Gillilanda, Syed Zahid Ali Shaha, Maria Gerasimenkoa, Michelle Tanga, Sarada Rajamanickama, Anika Yadatia, Lawrence B. Schonbergerd, Justin Greenleee, Qingzhong Konga,c, James A. Mastriannib, and Wen-Quan Zoua,c
aDepartment of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH, USA; bDepartment of Neurology and Center for Comprehensive Care and Research on Memory Disorders, the University of Chicago Pritzker School of Medicine, Chicago, USA; cNational Prion Disease Pathology Surveillance Center, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA; dDivision of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA, USA; eVirus and Prion Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, 1920 Dayton Avenue, Ames, IA, USA
Aims: Chronic wasting disease (CWD) results from the accumulation of an infectious misfolded conformer (PrPSc) of cellular prion protein (PrPC) in the brains of deer and elk. It has been spreading rapidly throughout many regions of North America, exported inadvertently to South Korea, and more recently identified in Europe. Mad cow disease has caused variant Creutzfeldt-Jakob disease (vCJD) in humans and is currently the only known zoonotic prion disease. Whether CWD is transmissible to humans remains uncertain. The aims of our study were not only to confirm whether CWD prion isolates can convert human brain PrPCinto PrPScin vitro by serial protein misfolding cyclic amplification (sPMCA) but also to determine whether the sPMCA-induced CWD-derived human PrPScis infectious.
Material and Methods: Eight CWD prion isolates from 7 elks and 1 deer were used as the seeds while normal human brain homogenates containing either PrP-129 MM (n = 2) or PrP-129 VV (n = 1) were used as the substrates for sPMCA assay. A normal elk brain tissue sample was used as a negative control seed. Two lines of humanized transgenic (Tg) mice expressing either human PrP-129VV or −129 MM polymorphism were included for transmission studies to determine the infectivity of PMCA-amplified PrPSc. Wester blotting and immunohistochemistry and hematoxylin & eosin staining were used for determining PrPScand neuropathological changes of inoculated animals.
Results: We report here the generation of the first CWD-derived infectious human PrPScusing elk CWD PrPScto initiate conversion of human PrPCfrom normal human brain homogenates with PMCA in vitro. Western blotting with a human PrP selective antibody confirmed that the PMCA-generated protease-resistant PrPScwas derived from the human brain PrPCsubstrate. Two lines of humanized transgenic mice expressing human PrPCwith either Val or Met at the polymorphic codon 129 developed clinical prion disease following intracerebral inoculation with the PMCA-generated CWD-derived human PrPSc. Diseased mice exhibited distinct PrPScpatterns and neuropathological changes in the brain.
Conclusions: Our study, using PMCA and animal bioassays, provides the first evidence that CWD PrPSchas the potential to overcome the species barrier and directly convert human PrPCinto infectious PrPScthat can produce bona fide prion disease when inoculated into humanized transgenic mice.
Funded by: CJD Foundation and NIH
Mortality surveillance of persons potentially exposed to chronic wasting disease
R.A. Maddoxa, R.F. Klosb, L.R. Willb, S.N. Gibbons-Burgenerb, A. Mvilongoa, J.Y. Abramsa, B.S. Applebyc, L.B. Schonbergera, and E.D. Belaya aNational Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention (CDC), Atlanta, USA; bWisconsin Department of Health Services (WDHS), Division of Public Health, Madison, USA; cNational Prion Disease Pathology Surveillance Center (NPDPSC), Case Western Reserve University, Cleveland, USA
Aims: It is unknown whether chronic wasting disease (CWD), a prion disease of cervids, can infect people, but consumption of meat from infected animals would be the most likely route of transmission. Wisconsin Department of Health Services, Division of Public Health (WDHS) personnel maintain a database consisting of information collected from hunters who reported eating, or an intention to eat, venison from CWD-positive cervids. These data, collected since 2003, allow for the evaluation of causes of mortality in individuals potentially exposed to CWD.
Material and Methods: The WDHS database contains the name, date of birth, when available, year of CWD-positive deer harvest, and city and state of residence for each potentially exposed individual. The database also includes information on how the deer was processed (self-processed or by a commercial operator) and when applicable, names of others with whom the venison was shared. Duplicate entries (i.e., those who consumed venison from CWD-positive deer in multiple hunt years) are determined by first name, last name, and date of birth. All names in the database are cross-checked with reported cases of human prion disease in Wisconsin and cases in the National Prion Disease Pathology Surveillance Center (NPDPSC) diagnostic testing database. Persons with date of birth available are also cross-checked with prion disease decedents identified through restricted-use national multiple cause-of-death data via a data use agreement with the National Center for Health Statistics (NCHS).
Results: The database currently consists of 1561 records for hunt years 2003–2017 and 87 additional records for 2018–2019. Of these, 657 records have accompanying date of birth; 15 entries were removed as duplicates leaving 642 unique individuals. Of these individuals, 278 of 426 (66%) who ate venison from a CWD-positive deer and provided processing information reported self-processing. No matches were found among any persons in the database cross-checked with WDHS human prion disease surveillance data, NPDPSC data (February 2022 update), and NCHS data through 2020.
Conclusions: Because of the linkage of person and CWD-positive animal in the WDHS database, reviewing the cause of mortality in potentially exposed persons is possible. The number of individuals cross-checked so far is likely only a small percentage of those potentially exposed to CWD in Wisconsin, and many more years of vital status tracking are needed given an expected long incubation period should transmission to humans occur. Nevertheless, the findings of this ongoing review are thus far reassuring.
Prion disease incidence, United States, 2003–2020
R.A. Maddoxa, M.K. Persona, K. Kotobellib, A. Mvilongoa, B.S. Applebyb, L.B. Schonbergera, T.A. Hammetta, J.Y. Abramsa, and E.D. Belaya aNational Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention (CDC), Atlanta, USA; bNational Prion Disease Pathology Surveillance Center (NPDPSC), Case Western Reserve University, Cleveland, USA
Aims: Mortality data, in conjunction with neuropathological and genetic testing results, are used to estimate prion disease incidence in the United States.
Material and Methods: Prion disease decedents for 2003–2020 were identified from restricted-use U.S. national multiple cause-of-death data, via a data use agreement with the National Center for Health Statistics, and from the National Prion Disease Pathology Surveillance Center (NPDPSC) database. NPDPSC decedents with neuropathological or genetic test results positive for prion disease for whom no likely match was found in the NCHS multiple cause-of-death data were added as cases for incidence calculations, while those with negative neuropathology results but with cause-of-death data indicating prion disease were removed. Unmatched cases in the NPDPSC database lacking neuropathological testing but with a positive real-time quaking-induced conversion (RT-QuIC) test result were additionally assessed. Age-specific and age-adjusted average annual incidence rates were calculated from the combined data; the year 2000 as the standard population and the direct method were used for age-adjustment.
Results: A total of 7,921 decedents were identified as having prion disease during 2003–2020 for an age-adjusted average annual incidence of 1.2 per million population. The age-adjusted incidence between males and females (1.3 and 1.1 per million, respectively) differed significantly (p < 0.0001). The age-specific average annual incidence among those <55 and ≥55 years of age was 0.2 and 4.8 per million, respectively; incidence among those ≥65 was 6.1 per million. Eighteen cases were <30 years of age for an age-specific incidence of 8.0 per billion; only 6 of these very young cases were sporadic (3 sporadic CJD, 3 sporadic fatal insomnia), with the rest being familial (9), variant (2), or iatrogenic (1). The age-adjusted annual incidence for the most recent year of data, 2020, was 1.3 per million. However, assessment of RT-QuIC positive cases lacking neuropathology in the NPDPSC database suggested that approximately 20% more cases may have occurred in that year; the addition of a subset of these cases that had date of death information available (n = 44) increased the 2020 rate to 1.4 per million.
Conclusions: Mortality data supplemented with the results of neuropathological, CSF RT-QuIC, and genetic testing can be used to estimate prion disease incidence. However, the identification in the NPDPSC database of RT-QuIC-positive cases lacking date of death information suggests that this strategy may exclude a number of probable prion disease cases. Prion disease cases <30 years of age, especially those lacking a pathogenic mutation, continue to be very rare.
Shedding of Chronic Wasting Disease Prions in Multiple Excreta Throughout Disease Course in White-tailed Deer
Nathaniel D. Denkersa, Erin E. McNultya, Caitlyn N. Krafta, Amy V. Nallsa, Joseph A. Westricha, Wilfred Goldmannb, Candace K. Mathiasona, and Edward A. Hoovera
aPrion Research Center, College of Veterinary Medicine and Biological Sciences, Department of Microbiology, Immunology, and Pathology; Colorado State University, Fort Collins, CO, USA; bDivision of Infection and Immunity, The Roslin Institute and the Royal Dick School of Veterinary Studies, University of Edinburgh, Midlothian, UK
Aims: Chronic wasting disease (CWD) now infects cervids in South Korea, North America, and Scandinavia. CWD is unique in its efficient transmission and shedding of prions in body fluids throughout long course infections. Questions remain as to the magnitude of shedding and the route of prion acquisition. As CWD continues to expand, the need to better understand these facets of disease becomes more pertinent. The purpose of the studies described was to define the longitudinal shedding profile of CWD prions in urine, saliva, and feces throughout the course of infection in white-tailed deer.
Material and Methods: Twelve (12) white-tailed deer were inoculated with either 1 mg or 300ng of CWD. Urine, saliva, and feces were collected every 3-month post-inoculation (MPI) throughout the study duration. Cohorts were established based on PNRP genotype: codon 96 GG (n = 6) and alternate codons 96 GS (n = 5) & 103NT (n = 1). Urine and saliva were analyzed using iron-oxide magnetic extraction (IOME) and real-time quaking induced conversion (RT-QuIC)(IQ). Feces were subjected to IOME, followed by 4 rounds protein misfolding cyclic amplification (PMCA) with products analyzed by RT-QuIC (IPQ). To determine whether IPQ may be superior to IQ, a subset of urine and saliva were also tested by IPQ. Results were compared with clinical disease status.
Results: Within the 96 GG cohort, positive seeding activity was detected in feces from all deer (100%), in saliva from 5 of 6 (83%), and in urine from 4 of 6 (66%). Shedding in all excreta occurred at, or just after, the first positive tonsil biopsy result. In the 96 GS/103NT cohort, positive seeding activity could be detected in feces from 3 of 6 (50%) deer, saliva in 2 of 6 (33%), and urine in 1 of 6 (16%). Shedding in excreta was detected >5 months after the first tonsil positive result. Four of six 96 GG deer developed clinical signs of CWD, whereas only 2 of the 96 GS/103NT did. Shedding was more frequently detected in deer with clinical disease. The IPQ protocol did not significantly improve detection in saliva or urine samples, however, it significantly augmented detection in feces by eliminating non-specific background commonly experienced with IQ. Negative control samples remained negative in samples tested.
Conclusions: These studies demonstrate: (a) CWD prion excretion occurs throughout infection; (2) PRNP genotype (GG≫GS/NT) influences the excreta shedding; and (3) detection sensitivity in excreta can vary with different RT-QuIC protocols. These results provide a more complete perspective of prion shedding in deer during the course of CWD infection.
Funded by: National Institutes of Health (NIH)
Grant number: RO1-NS061902-09 R to EAH, PO1-AI077774 to EAH, and R01-AI112956-06 to CKM
Acknowledgement: We abundantly thank Sallie Dahmes at WASCO and David Osborn and Gino D’Angelo at the University of Georgia Warnell School of Forestry and Natural Resources for their long-standing support of this work through provision of the hand-raised, CWD-free, white-tailed deer used in these studies
Large-scale PMCA screening of retropharyngeal lymph nodes and in white-tailed deer and comparisons with ELISA and IHC: the Texas CWD study
Rebeca Benaventea, Paulina Sotoa, Mitch Lockwoodb, and Rodrigo Moralesa
aDepartment of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Texas, USA; bTexas Park and Wildlife Department, Texas, USA
Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy that affects various species of cervids, and both free-ranging and captive animals. Until now, CWD has been detected in 3 continents: North America, Europe, and Asia. CWD prevalence in some states may reach 30% of total animals. In Texas, the first case of CWD was reported in a free-range mule deer in Hudspeth and now it has been detected in additional 14 counties. Currently, the gold standard techniques used for CWD screening and detection are ELISA and immunohistochemistry (IHC) of obex and retropharyngeal lymph nodes (RPLN). Unfortunately, these methods are known for having a low diagnostic sensitivity. Hence, many CWD-infected animals at pre-symptomatic stages may be misdiagnosed. Two promising in vitro prion amplification techniques, including the real-time quaking-induced conversion (RT-QuIC) and the protein misfolding cyclic amplification (PMCA) have been used to diagnose CWD and other prion diseases in several tissues and bodily fluids. Considering the low cost and speed of RT-QuIC, two recent studies have communicated the potential of this technique to diagnose CWD prions in RPLN samples. Unfortunately, the data presented in these articles suggest that identification of CWD positive samples is comparable to the currently used ELISA and IHC protocols. Similar studies using the PMCA technique have not been reported.
Aims: Compare the CWD diagnostic potential of PMCA with ELISA and IHC in RPLN samples from captive and free-range white-tailed deer. Material and Methods: In this study we analyzed 1,003 RPLN from both free-ranging and captive white-tailed deer collected in Texas. Samples were interrogated with the PMCA technique for their content of CWD prions. PMCA data was compared with the results obtained through currently approved techniques.
Results: Our results show a 15-fold increase in CWD detection in free-range deer compared with ELISA. Our results unveil the presence of prion infected animals in Texas counties with no previous history of CWD. In the case of captive deer, we detected a 16% more CWD positive animals when compared with IHC. Interestingly, some of these positive samples displayed differences in their electroforetic mobilities, suggesting the presence of different prion strains within the State of Texas.
Conclusions: PMCA sensitivity is significantly higher than the current gold standards techniques IHC and ELISA and would be a good tool for rapid CWD screening.
Funded by: USDA
Grant number: AP20VSSPRS00C143
ATYPRION project: assessing the zoonotic potential of interspecies transmission of CWD isolates to livestock (preliminary results).
Enric Vidala,b, Juan Carlos Espinosac, Samanta Gilera,b, Montserrat Ordóñeza,b, Guillermo Canteroa,b, Vincent Béringued, Justin J. Greenleee, and Juan Maria Torresc
aUnitat mixta d’Investigació IRTA-UAB en Sanitat Animal. Centre de Recerca en Sanitat Animal (CReSA). Campus de la Universitat Autònoma de Barcelona (UAB), Bellaterra, Catalonia; bIRTA. Programa de Sanitat Animal. Centre de Recerca en Sanitat Animal (CReSA). Campus de la Universitat Autònoma de Barcelona (UAB), Bellaterra, Catalonia; cCentro de Investigación en Sanidad Animal, CISA-INIA-CSIC, Valdeolmos, Madrid, Spain; dMolecular Virology and Immunology, French National Research Institute for Agriculture, Food and Environment (INRAE), Université Paris-Saclay, Jouy-en-Josas, France; eVirus and Prion Research Unit, National Animal Disease Center, ARS, United States Department of Agriculture, Ames, IA, USA
Aims: Since variant Creutzfeldt-Jackob disease was linked to the consumption of bovine spongiform encephalopathy prions, the study of the pathobiological features of animal prions, particularly their zoonotic potential, is of great concern to the scientific community and public health authorities. Furthermore, interspecies transmission of prions has been demonstrated as a putative evolutionary mechanism for prions, that can lead to the emergence of new features including the ability to infect humans. For instance, small ruminants’ atypical scrapie prions, when propagated in a bovine or porcine host, can shift to a classical BSE phenotype thus posing a potential risk in case of human exposure. So far, no hard evidence of zoonotic transmission of cervids’ chronic wasting disease (CWD) to humans has been published, however experimental transmission to bovine, ovine and caprine hosts has been achieved. Our goal is to investigate if, once passaged through these domestic species, CWD prions might become infectious to humans.
Material and Methods: Different CWD isolates experimentally adapted to cattle, sheep and goat (Hamir et al, 2005, 2006, 2007, Greenlee et al 2012) have been intracerebrally inoculated to transgenic mouse models expressing the human cellular prion protein either homozygous for methionine or valine at codon 129 (Tg340-Met129 and Tg362-Val129). Additionally, inocula obtained from experimental transmission of elk CWD to ovinized (Tg501) and bovinized (BoTg110) transgenic mice, as well as white-tailed deer CWD to BoTg110 mice, are currently being bioassayed in both human PrPCtransgenic models.
Results and conclusions: No evidence of transmission has been found on first passage for bovine adapted elk and mule deer CWD to none of the humanized models. The remaining bioassays are ongoing without showing clinical signs yet, as well as second passages for the negative 1stpassages.
Funded by: La Marató de TV3 foundation. Grant number: ATYPRION (201,821–30-31-32)
PRION CONFERENCE 2022 ABSTRACTS CWD TSE PrP ZOONOSIS and ENVIRONMENTAL FACTORS
Chronic wasting disease detection in environmental and biological samples from a taxidermy site
Paulina Sotoa,b, J. Hunter Reedc, Mitch Lockwoodc, and Rodrigo Moralesa,b aDepartment of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Texas, USA; bUniversidad Bernardo O’Higgins, Santiago, Chile; cTexas Parks and Wildlife Department, Texas, USA
Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy affecting captive and free-ranging cervids (e.g., mule deer, white-tailed deer, elk, reindeer, and moose). Nowadays, CWD is widely distributed in North America. It is suggested that CWD spreads due to direct animal contact or through exposure to contaminated environments previously inhabited by infected animals. CWD may also be spread through the movement of infected animals and carcasses. Taxidermy practices involve processing deer tissues (or whole animal carcasses). In many cases, the CWD status of processed animals is unknown. This can generate risks of disease spread and transmission. Taxidermy practices include different steps involving physical, chemical, and biological procedures. Without proper tissue handling or disposal practices, taxidermist facilities may become a focus of prion infectivity. Aims: In this study, we evaluated the presence of infectious prions in a taxidermy facility believed to be exposed to CWD. Detection was performed using the Protein Misfolding Cyclic Amplification (PMCA) technique in biological and inert environmental samples. Methods: We collected biological and environmental samples (plants, soils, insects, excreta, and others) from a taxidermy facility, and we tested these samples using the PMCA technique. In addition, we swabbed different surfaces possibly exposed to CWD-infected animals. For the PMCA reaction, we directly used a swab piece or 10 µL of 20% w/v homogenized samples. Results: The PMCA analysis demonstrated CWD seeding activity in some of the components of this facility, including insects involved in head processing, soils, and a trash dumpster. Conclusions: Different areas of this property were used for various taxidermy procedures. We were able to detect the presence of prions in i) soils that were in contact with the heads of dead animals, ii) insects involved in the cleaning of skulls, and iii) an empty dumpster where animal carcasses were previously placed. This is the first report demonstrating that swabbing is a helpful method to screen for prion infectivity on surfaces potentially contaminated with CWD. These findings are relevant as this swabbing and amplification strategy may be used to evaluate the disease status of other free-ranging and captive settings where there is a concern for CWD transmissions, such as at feeders and water troughs with CWD-exposed properties. This approach could have substantial implications for free-ranging cervid surveillance as well as in epidemiological investigations of CWD.
Funded by: USDA Grant number: AP20VSSPRS00C143
Large-scale PMCA screening of retropharyngeal lymph nodes and in white-tailed deer and comparisons with ELISA and IHC: the Texas CWD study
Rebeca Benaventea, Paulina Sotoa, Mitch Lockwoodb, and Rodrigo Moralesa aDepartment of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Texas, USA; bTexas Park and Wildlife Department, Texas, USA
Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy that affects various species of cervids, and both free-ranging and captive animals. Until now, CWD has been detected in 3 continents: North America, Europe, and Asia. CWD prevalence in some states may reach 30% of total animals. In Texas, the first case of CWD was reported in a free-range mule deer in Hudspeth and now it has been detected in additional 14 counties. Currently, the gold standard techniques used for CWD screening and detection are ELISA and immunohistochemistry (IHC) of obex and retropharyngeal lymph nodes (RPLN). Unfortunately, these methods are known for having a low diagnostic sensitivity. Hence, many CWD-infected animals at pre-symptomatic stages may be misdiagnosed. Two promising in vitro prion amplification techniques, including the real-time quaking-induced conversion (RT-QuIC) and the protein misfolding cyclic amplification (PMCA) have been used to diagnose CWD and other prion diseases in several tissues and bodily fluids. Considering the low cost and speed of RT-QuIC, two recent studies have communicated the potential of this technique to diagnose CWD prions in RPLN samples. Unfortunately, the data presented in these articles suggest that identification of CWD positive samples is comparable to the currently used ELISA and IHC protocols. Similar studies using the PMCA technique have not been reported. Aims: Compare the CWD diagnostic potential of PMCA with ELISA and IHC in RPLN samples from captive and free-range white-tailed deer. Material and Methods: In this study we analyzed 1,003 RPLN from both free-ranging and captive white-tailed deer collected in Texas. Samples were interrogated with the PMCA technique for their content of CWD prions. PMCA data was compared with the results obtained through currently approved techniques. Results: Our results show a 15-fold increase in CWD detection in free-range deer compared with ELISA. Our results unveil the presence of prion infected animals in Texas counties with no previous history of CWD. In the case of captive deer, we detected a 16% more CWD positive animals when compared with IHC. Interestingly, some of these positive samples displayed differences in their electroforetic mobilities, suggesting the presence of different prion strains within the State of Texas. Conclusions: PMCA sensitivity is significantly higher than the current gold standards techniques IHC and ELISA and would be a good tool for rapid CWD screening.
Funded by: USDA Grant number: AP20VSSPRS00C143
Protein misfolding cyclic amplification (PMCA) as an ultra-sensitive technique for the screening of CWD prions in different sample types
Francisca Bravo‐Risia,b, Paulina Sotoa,b, Rebeca Benaventea, Hunter Reedc, Mitch Lockwoodc, Tracy Nicholsd, and Rodrigo Moralesa,b aDepartment of Neurology, The University of Texas Health Science Center at Houston, Houston, TX, USA; bCentro Integrativo de Biologia y Quimica Aplicada (CIBQA), Universidad Bernardo O’Higgins, Santiago, Chile; cTexas Park and Wildlife Department, Texas, USA; dVeterinary Services Cervid Health Program, United States Department of Agriculture, Animal and Plant Health Inspection Service, Fort Collins, Colorado, USA
Chronic wasting disease (CWD) is a prion disease that affects farmed and free-ranging cervids. The infectious agent in CWD is a misfolded form of the prion protein (PrPSc) that promotes conformational changes in the host’s cellular prion protein (PrPC). Currently, definitive CWD status is confirmed in the brain and lymphoid tissues by immunohistochemistry. The limitation of this technique is its poor sensitivity. Protein misfolding cyclic amplification (PMCA) and real-time quaking-induced conversion (RT- QuIC) are ultra-sensitive techniques that overcome these issues. PMCA mimics the self- propagation of infectious prions in vitro through multiple incubation/sonication cycles, increasing the number of prion particles present in a given sample. The detection of proteinase K (PK) -resistant PrPScby PMCA has been performed in experimental and natural samples that might harbor subclinical levels of prions. These samples include several tissues, bodily fluids, excreta, and different manmade and natural materials, including mineral licks, soils, and plants. Aims: In this study, we highlight recent advances and contributions that our group has performed in the detection of CWD prions from samples collected in farmed and free-ranging cervids, as well as other specimens involving the environment that contains CWD-infected deer. Material and Methods: A set of diverse samples analyzed in this study were collected by USDA and TPWD personnel in breeding and taxidermy facilities, and deer breeding facilities. These included animal and environmental samples. Additional samples from free-ranging animals were provided by hunters. Results: The diverse range of samples successfully detected for CWD prion infection in this study include blood, semen, feces, obex, retropharyngeal lymph node, fetuses (neural and peripheral tissues) and gestational tissues, parasites, insects, plants, compost/soil mixtures, and swabs from trash containers. Importantly, these results helped to identify seeding-competent prions in places reported to be free of CWD. The levels of prion infectivity in most of these samples are currently being investigated. Conclusions: Our findings contribute to the understanding of the transmission dynamics and prevalence of CWD. In addition, our data have helped to identify CWD in areas previously considered to be free of CWD. We also demonstrate that PMCA is a powerful technique for the screening of biological and environmental samples. Overall, our research suggests that PMCA may be a useful tool to implement for the surveillance and management of CWD. Funded by: NIH/NIAID and USDA Grant number: 1R01AI132695 (NIH) and AP20VSSPRS00C143 (USDA)
Nasal bot: an emerging vector for natural chronic wasting disease transmission
Paulina Sotoa,b, Francisca Bravo-Risia,b, Carlos Kramma, Nelson Pereza, Rebeca Benaventea, J. Hunter Reedc, Mitch Lockwoodc, Tracy A. Nicholsd, and Rodrigo Moralesa,b aDepartment of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Texas, USA; bUniversidad Bernardo O’Higgins, Santiago, Chile; cTexas Park and Wildlife Department, Texas, USA; dVeterinary Services Cervid Health Program, United States Department of Agriculture, Animal and Plant Health Inspection Service, Fort Collins, Colorado, USA
Chronic wasting disease (CWD) is a fatal neurodegenerative disease that affects farmed and free-ranging cervids populations. The spread of CWD in cervids is thought to occur through the direct contact between cervids or through the exposure of naïve animals to contaminated environments. Parasites are known vectors of multiple diseases in animals. However, the potential role of parasites in CWD transmission remains unclear. Aims: The main objective of this study was to determine if CWD prions could be detected in the larvae of deer nasal bot flies, a common deer parasite, taken from CWD-infected white-tailed deer (Odocoileus virginianus). Methods: Bot fly larvae were collected from the nasal cavity of naturally infected CWD- positive or CWD non-detect white-tailed deer. The CWD seeding activity of the larvae was interrogated by PMCA. Prion infectivity was also evaluated in cervidized transgenic mouse bioassay (intra-cerebral administration in Tg1536 mice). Mice inoculated with bot larvae homogenate were sacrificed when they showed established signs of prion disease, or at extended periods after treatment (600 days). All inoculated mouse brains were evaluated for protease resistant prions to confirm clinical or sub-clinical infection. Bot larvae from CWD non-detect deer were used as controls. To further mimic environmental transmission, bot larvae homogenates were mixed with soils and plants were grown on them. Both plants and soils were tested for prion seeding activity. Results: PMCA analysis demonstrated CWD seeding activity in nasal bot larvae from captive and free-ranging white-tailed deer. CWD-contaminated bots efficiently infected transgenic mice, with attack rates and incubation periods suggesting high infectivity titers. Further analyses of treated animals (biochemical characterization of protease resistant prions and immunohistochemistry) confirmed prion infection. Analyses on dissected parts of the bot larvae demonstrate that the infectivity is concentrated in the larvae cuticle (outer part). Nasal bot larvae extracts mixed with
soils showed seeding activity by PMCA. Interestingly, plants grown in soil contaminated with the nasal bot larvae extract were found to produce seeding activity by PMCA. Conclusion: In this study we described for the first time that deer nasal bot larvae from CWD-infected deer carry high CWD infectivity titers. We also demonstrate that CWD prions in these parasites can interact with other environmental components relevant for disease transmission. Considering this information, we propose that deer nasal bot larvae could act as vectors for CWD transmission in wild and farming settings. Funded by: NIH/NIAID and USDA/APHIS Grant number: R01AI132695 and AP20VSSPRS00C143 PRION 2022 ABSTRACTS, AND A BIG THANK YOU TO On behalf of the Prion2020/2022 Congress Organizing Committee and the NeuroPrion Association, we heartily invite you to join us for the International Conference Prion2020/2022 from 13.-16. September 2022 in Göttingen.
Prion 2022 Conference abstracts: pushing the boundaries
Shedding of Chronic Wasting Disease Prions in Multiple Excreta Throughout Disease Course in White-tailed Deer
Nathaniel D. Denkersa, Erin E. McNultya, Caitlyn N. Krafta, Amy V. Nallsa, Joseph A. Westricha, Wilfred Goldmannb, Candace K. Mathiasona, and Edward A. Hoovera
aPrion Research Center, College of Veterinary Medicine and Biological Sciences, Department of Microbiology, Immunology, and Pathology; Colorado State University, Fort Collins, CO, USA; bDivision of Infection and Immunity, The Roslin Institute and the Royal Dick School of Veterinary Studies, University of Edinburgh, Midlothian, UK
Aims: Chronic wasting disease (CWD) now infects cervids in South Korea, North America, and Scandinavia. CWD is unique in its efficient transmission and shedding of prions in body fluids throughout long course infections. Questions remain as to the magnitude of shedding and the route of prion acquisition. As CWD continues to expand, the need to better understand these facets of disease becomes more pertinent. The purpose of the studies described was to define the longitudinal shedding profile of CWD prions in urine, saliva, and feces throughout the course of infection in white-tailed deer.
Material and Methods: Twelve (12) white-tailed deer were inoculated with either 1 mg or 300ng of CWD. Urine, saliva, and feces were collected every 3-month post-inoculation (MPI) throughout the study duration. Cohorts were established based on PNRP genotype: codon 96 GG (n = 6) and alternate codons 96 GS (n = 5) & 103NT (n = 1). Urine and saliva were analyzed using iron-oxide magnetic extraction (IOME) and real-time quaking induced conversion (RT-QuIC)(IQ). Feces were subjected to IOME, followed by 4 rounds protein misfolding cyclic amplification (PMCA) with products analyzed by RT-QuIC (IPQ). To determine whether IPQ may be superior to IQ, a subset of urine and saliva were also tested by IPQ. Results were compared with clinical disease status.
Results: Within the 96 GG cohort, positive seeding activity was detected in feces from all deer (100%), in saliva from 5 of 6 (83%), and in urine from 4 of 6 (66%). Shedding in all excreta occurred at, or just after, the first positive tonsil biopsy result. In the 96 GS/103NT cohort, positive seeding activity could be detected in feces from 3 of 6 (50%) deer, saliva in 2 of 6 (33%), and urine in 1 of 6 (16%). Shedding in excreta was detected >5 months after the first tonsil positive result. Four of six 96 GG deer developed clinical signs of CWD, whereas only 2 of the 96 GS/103NT did. Shedding was more frequently detected in deer with clinical disease. The IPQ protocol did not significantly improve detection in saliva or urine samples, however, it significantly augmented detection in feces by eliminating non-specific background commonly experienced with IQ. Negative control samples remained negative in samples tested.
Conclusions: These studies demonstrate: (a) CWD prion excretion occurs throughout infection; (2) PRNP genotype (GG≫GS/NT) influences the excreta shedding; and (3) detection sensitivity in excreta can vary with different RT-QuIC protocols. These results provide a more complete perspective of prion shedding in deer during the course of CWD infection.
Funded by: National Institutes of Health (NIH)
Grant number: RO1-NS061902-09 R to EAH, PO1-AI077774 to EAH, and R01-AI112956-06 to CKM
Acknowledgement: We abundantly thank Sallie Dahmes at WASCO and David Osborn and Gino D’Angelo at the University of Georgia Warnell School of Forestry and Natural Resources for their long-standing support of this work through provision of the hand-raised, CWD-free, white-tailed deer used in these studies
Carrot plants as potential vectors for CWD transmission
Paulina Sotoa,b, Francisca Bravo-Risia,b, Claudio Sotoa, and Rodrigo Moralesa,b
aDepartment of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Texas, USA; bUniversidad Bernardo O’Higgins, Santiago, Chile
Prion diseases are infectious neurodegenerative disorders afflicting humans and other mammals. These diseases are generated by the misfolding of the cellular prion protein into a disease-causing isoform. Chronic wasting disease (CWD) is a prevalent prion disease affecting cervids (captive and free-range). CWD is thought to be transmitted through direct animal contact or by indirect exposure to contaminated environments. Many studies have shown that infectious prions can enter the environment through saliva, feces, or urine from infected animals and decaying carcasses. However, we do not fully understand the specific contribution of each component to disease transmission events. Plants are logical environmental components to be evaluated since they grow in environments contaminated with CWD prions and are relevant for animal and human nutrition.
Aims: The main objective of this study is to study whether prions are transported to the roots and leaves of carrots, an edible plant commonly used in the human diet and as deer bait.
Methods: We have grown carrot plants in CWD-infected soils. After 90 days, we harvested the carrots and separated them from the leaves. The experiment was controlled by growing plants in soil samples treated with brain extracts from healthy animals. These materials were interrogated for their prion seeding activity using the Protein Misfolding Cyclic Amplification (PMCA) technique. Infectivity was evaluated in mouse bioassays (intracerebral injections in Tg1536 mice). The animals were sacrificed when they showed established signs of prion disease. Animals not displaying clinical signs were sacrificed at 600 days post-inoculation.
Results: The PMCA analysis demonstrated CWD seeding activity in soils contaminated with CWD prions, as well as in carrot plants (leaves and roots) grown on them. Bioassays demonstrated that both leaves and roots contained CWD prions in sufficient quantities to induce disease (92% attack rate). As expected, animals treated with prion-infected soils developed prion disease at shorter incubation periods (and complete attack rates) compared to plant components. Animals treated with soil and plant components exposed with CWD-free brain extracts did not display prion-associated clinical signs or evidence of sub-clinical prion infection.
Conclusions: We show that edible plant components can absorb prions from CWD contaminated soils and transport them to their aerial parts. Our results indicate that plants could participate as vectors of CWD transmission. Importantly, plants designated for human consumption represent a risk of introducing CWD prions into the human food chain.
Funded by: NIH
Grant number: R01AI132695
8. Even though human TSE‐exposure risk through consumption of game from European cervids can be assumed to be minor, if at all existing, no final conclusion can be drawn due to the overall lack of scientific data. In particular the US data do not clearly exclude the possibility of human (sporadic or familial) TSE development due to consumption of venison. The Working Group thus recognizes a potential risk to consumers if a TSE would be present in European cervids. It might be prudent considering appropriate measures to reduce such a risk, e.g. excluding tissues such as CNS and lymphoid tissues from the human food chain, which would greatly reduce any potential risk for consumers. However, it is stressed that currently, no data regarding a risk of TSE infections from cervid products are available.
''These observations support the view that a truly infectious TSE agent, unrecognized until recently, infects sheep and goat flocks and may have important implications in terms of scrapie control and public health.''
Prion Conference 2018 Abstracts
BSE aka MAD COW DISEASE, was first discovered in 1984, and it took until 1995 to finally admit that BSE was causing nvCJD, the rest there is history, but that science is still evolving i.e. science now shows that indeed atypical L-type BSE, atypical Nor-98 Scrapie, and typical Scrapie are all zoonosis, zoonotic for humans, there from.
HOW long are we going to wait for Chronic Wasting Disease, CWD TSE Prion of Cervid, and zoonosis, zoonotic tranmission to humans there from?
Studies have shown since 1994 that humans are susceptible to CWD TSE Prion, so, what's the hold up with making CWD a zoonotic zoonosis disease, the iatrogenic transmissions there from is not waiting for someone to make a decision.
Prion Conference 2018 Abstracts
P190 Human prion disease mortality rates by occurrence of chronic wasting disease in freeranging cervids, United States
Abrams JY (1), Maddox RA (1), Schonberger LB (1), Person MK (1), Appleby BS (2), Belay ED (1)
(1) Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases, Atlanta, GA, USA (2) Case Western Reserve University, National Prion Disease Pathology Surveillance Center (NPDPSC), Cleveland, OH, USA.
Background
Chronic wasting disease (CWD) is a prion disease of deer and elk that has been identified in freeranging cervids in 23 US states. While there is currently no epidemiological evidence for zoonotic transmission through the consumption of contaminated venison, studies suggest the CWD agent can cross the species barrier in experimental models designed to closely mimic humans. We compared rates of human prion disease in states with and without CWD to examine the possibility of undetermined zoonotic transmission.
Methods
Death records from the National Center for Health Statistics, case records from the National Prion Disease Pathology Surveillance Center, and additional state case reports were combined to create a database of human prion disease cases from 2003-2015. Identification of CWD in each state was determined through reports of positive CWD tests by state wildlife agencies. Age- and race-adjusted mortality rates for human prion disease, excluding cases with known etiology, were determined for four categories of states based on CWD occurrence: highly endemic (>16 counties with CWD identified in free-ranging cervids); moderately endemic (3-10 counties with CWD); low endemic (1-2 counties with CWD); and no CWD states. States were counted as having no CWD until the year CWD was first identified. Analyses stratified by age, sex, and time period were also conducted to focus on subgroups for which zoonotic transmission would be more likely to be detected: cases <55 years old, male sex, and the latter half of the study (2010-2015).
Results
Highly endemic states had a higher rate of prion disease mortality compared to non-CWD states (rate ratio [RR]: 1.12, 95% confidence interval [CI] = 1.01 - 1.23), as did low endemic states (RR: 1.15, 95% CI = 1.04 - 1.27). Moderately endemic states did not have an elevated mortality rate (RR: 1.05, 95% CI = 0.93 - 1.17). In age-stratified analyses, prion disease mortality rates among the <55 year old population were elevated for moderately endemic states (RR: 1.57, 95% CI = 1.10 – 2.24) while mortality rates were elevated among those ≥55 for highly endemic states (RR: 1.13, 95% CI = 1.02 - 1.26) and low endemic states (RR: 1.16, 95% CI = 1.04 - 1.29). In other stratified analyses, prion disease mortality rates for males were only elevated for low endemic states (RR: 1.27, 95% CI = 1.10 - 1.48), and none of the categories of CWD-endemic states had elevated mortality rates for the latter time period (2010-2015).
Conclusions
While higher prion disease mortality rates in certain categories of states with CWD in free-ranging cervids were noted, additional stratified analyses did not reveal markedly elevated rates for potentially sensitive subgroups that would be suggestive of zoonotic transmission. Unknown confounding factors or other biases may explain state-by-state differences in prion disease mortality.
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P172 Peripheral Neuropathy in Patients with Prion Disease
Wang H(1), Cohen M(1), Appleby BS(1,2)
(1) University Hospitals Cleveland Medical Center, Cleveland, Ohio (2) National Prion Disease Pathology Surveillance Center, Cleveland, Ohio.
Prion disease is a fatal progressive neurodegenerative disease due to deposition of an abnormal protease-resistant isoform of prion protein. Typical symptoms include rapidly progressive dementia, myoclonus, visual disturbance and hallucinations. Interestingly, in patients with prion disease, the abnormal protein canould also be found in the peripheral nervous system. Case reports of prion deposition in peripheral nerves have been reported. Peripheral nerve involvement is thought to be uncommon; however, little is known about the exact prevalence and features of peripheral neuropathy in patients with prion disease.
We reviewed autopsy-proven prion cases from the National Prion Disease Pathology Surveillance Center that were diagnosed between September 2016 to March 2017. We collected information regarding prion protein diagnosis, demographics, comorbidities, clinical symptoms, physical exam, neuropathology, molecular subtype, genetics lab, brain MRI, image and EMG reports. Our study included 104 patients. Thirteen (12.5%) patients had either subjective symptoms or objective signs of peripheral neuropathy. Among these 13 patients, 3 had other known potential etiologies of peripheral neuropathy such as vitamin B12 deficiency or prior chemotherapy. Among 10 patients that had no other clear etiology, 3 (30%) had familial CJD. The most common sCJD subtype was MV1-2 (30%), followed by MM1-2 (20%). The Majority of cases wasere male (60%). Half of them had exposure to wild game. The most common subjective symptoms were tingling and/or numbness of distal extremities. The most common objective finding was diminished vibratory sensation in the feet. Half of them had an EMG with the findings ranging from fasciculations to axonal polyneuropathy or demyelinating polyneuropathy.
Our study provides an overview of the pattern of peripheral neuropathy in patients with prion disease. Among patients with peripheral neuropathy symptoms or signs, majority has polyneuropathy. It is important to document the baseline frequency of peripheral neuropathy in prion diseases as these symptoms may become important when conducting surveillance for potential novel zoonotic prion diseases.
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P177 PrP plaques in methionine homozygous Creutzfeldt-Jakob disease patients as a potential marker of iatrogenic transmission
Abrams JY (1), Schonberger LB (1), Cali I (2), Cohen Y (2), Blevins JE (2), Maddox RA (1), Belay ED (1), Appleby BS (2), Cohen ML (2)
(1) Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases, Atlanta, GA, USA (2) Case Western Reserve University, National Prion Disease Pathology Surveillance Center (NPDPSC), Cleveland, OH, USA.
Background
Sporadic Creutzfeldt-Jakob disease (CJD) is widely believed to originate from de novo spontaneous conversion of normal prion protein (PrP) to its pathogenic form, but concern remains that some reported sporadic CJD cases may actually be caused by disease transmission via iatrogenic processes. For cases with methionine homozygosity (CJD-MM) at codon 129 of the PRNP gene, recent research has pointed to plaque-like PrP deposition as a potential marker of iatrogenic transmission for a subset of cases. This phenotype is theorized to originate from specific iatrogenic source CJD types that comprise roughly a quarter of known CJD cases.
Methods
We reviewed scientific literature for studies which described PrP plaques among CJD patients with known epidemiological links to iatrogenic transmission (receipt of cadaveric human grown hormone or dura mater), as well as in cases of reported sporadic CJD. The presence and description of plaques, along with CJD classification type and other contextual factors, were used to summarize the current evidence regarding plaques as a potential marker of iatrogenic transmission. In addition, 523 cases of reported sporadic CJD cases in the US from January 2013 through September 2017 were assessed for presence of PrP plaques.
Results
We identified four studies describing 52 total cases of CJD-MM among either dura mater recipients or growth hormone recipients, of which 30 were identified as having PrP plaques. While sporadic cases were not generally described as having plaques, we did identify case reports which described plaques among sporadic MM2 cases as well as case reports of plaques exclusively in white matter among sporadic MM1 cases. Among the 523 reported sporadic CJD cases, 0 of 366 MM1 cases had plaques, 2 of 48 MM2 cases had kuru plaques, and 4 of 109 MM1+2 cases had either kuru plaques or both kuru and florid plaques. Medical chart review of the six reported sporadic CJD cases with plaques did not reveal clinical histories suggestive of potential iatrogenic transmission.
Conclusions
PrP plaques occur much more frequently for iatrogenic CJD-MM cases compared to sporadic CJDMM cases. Plaques may indicate iatrogenic transmission for CJD-MM cases without a type 2 Western blot fragment. The study results suggest the absence of significant misclassifications of iatrogenic CJD as sporadic. To our knowledge, this study is the first to describe grey matter kuru plaques in apparently sporadic CJD-MM patients with a type 2 Western blot fragment.
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P180 Clinico-pathological analysis of human prion diseases in a brain bank series
Ximelis T (1), Aldecoa I (1,2), Molina-Porcel L (1,3), Grau-Rivera O (4), Ferrer I (5), Nos C (6), Gelpi E (1,7), Sánchez-Valle R (1,4)
(1) Neurological Tissue Bank of the Biobanc-Hospital ClÃnic-IDIBAPS, Barcelona, Spain (2) Pathological Service of Hospital ClÃnic de Barcelona, Barcelona, Spain (3) EAIA Trastorns Cognitius, Centre Emili Mira, Parc de Salut Mar, Barcelona, Spain (4) Department of Neurology of Hospital ClÃnic de Barcelona, Barcelona, Spain (5) Institute of Neuropathology, Hospital Universitari de Bellvitge, Hospitalet de Llobregat, Barcelona (6) General subdirectorate of Surveillance and Response to Emergencies in Public Health, Department of Public Health in Catalonia, Barcelona, Spain (7) Institute of Neurology, Medical University of Vienna, Vienna, Austria.
Background and objective:
The Neurological Tissue Bank (NTB) of the Hospital Clínic-Institut d‘Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain is the reference center in Catalonia for the neuropathological study of prion diseases in the region since 2001. The aim of this study is to analyse the characteristics of the confirmed prion diseases registered at the NTB during the last 15 years.
Methods:
We reviewed retrospectively all neuropathologically confirmed cases registered during the period January 2001 to December 2016.
Results:
176 cases (54,3% female, mean age: 67,5 years and age range: 25-86 years) of neuropathological confirmed prion diseases have been studied at the NTB. 152 cases corresponded to sporadic Creutzfeldt-Jakob disease (sCJD), 10 to genetic CJD, 10 to Fatal Familial Insomnia, 2 to GerstmannSträussler-Scheinker disease, and 2 cases to variably protease-sensitive prionopathy (VPSPr). Within sCJD subtypes the MM1 subtype was the most frequent, followed by the VV2 histotype.
Clinical and neuropathological diagnoses agreed in 166 cases (94%). The clinical diagnosis was not accurate in 10 patients with definite prion disease: 1 had a clinical diagnosis of Fronto-temporal dementia (FTD), 1 Niemann-Pick‘s disease, 1 Lewy Body‘s Disease, 2 Alzheimer‘s disease, 1 Cortico-basal syndrome and 2 undetermined dementia. Among patients with VPSPr, 1 had a clinical diagnosis of Amyotrophic lateral sclerosis (ALS) and the other one with FTD.
Concomitant pathologies are frequent in older age groups, mainly AD neuropathological changes were observed in these subjects.
Discussion:
A wide spectrum of human prion diseases have been identified in the NTB being the relative frequencies and main characteristics like other published series. There is a high rate of agreement between clinical and neuropathological diagnoses with prion diseases. These findings show the importance that public health has given to prion diseases during the past 15 years. Continuous surveillance of human prion disease allows identification of new emerging phenotypes. Brain tissue samples from these donors are available to the scientific community. For more information please visit:
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P192 Prion amplification techniques for the rapid evaluation of surface decontamination procedures
Bruyere-Ostells L (1), Mayran C (1), Belondrade M (1), Boublik Y (2), Haïk S (3), Fournier-Wirth C (1), Nicot S (1), Bougard D (1)
(1) Pathogenesis and control of chronic infections, Etablissement Français du Sang, Inserm, Université de Montpellier, Montpellier, France. (2) Centre de Recherche en Biologie cellulaire de Montpellier, CNRS, Université de Montpellier, Montpellier, France. (3) Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Université Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France.
Aims:
Transmissible Spongiform Encephalopathies (TSE) or prion diseases are a group of incurable and always fatal neurodegenerative disorders including Creutzfeldt-Jakob diseases (CJD) in humans. These pathologies include sporadic (sCJD), genetic and acquired (variant CJD) forms. By the past, sCJD and vCJD were transmitted by different prion contaminated biological materials to patients resulting in more than 400 iatrogenic cases (iCJD). The atypical nature and the biochemical properties of the infectious agent, formed by abnormal prion protein or PrPTSE, make it particularly resistant to conventional decontamination procedures. In addition, PrPTSE is widely distributed throughout the organism before clinical onset in vCJD and can also be detected in some peripheral tissues in sporadic CJD. Risk of iatrogenic transmission of CJD by contaminated medical device remains thus a concern for healthcare facilities. Bioassay is the gold standard method to evaluate the efficacy of prion decontamination procedures but is time-consuming and expensive. Here, we propose to compare in vitro prion amplification techniques: Protein Misfolding Cyclic Amplification (PMCA) and Real-Time Quaking Induced Conversion (RT-QuIC) for the detection of residual prions on surface after decontamination.
Methods:
Stainless steel wires, by mimicking the surface of surgical instruments, were proposed as a carrier model of prions for inactivation studies. To determine the sensitivity of the two amplification techniques on wires (Surf-PMCA and Surf-QuIC), steel wires were therefore contaminated with serial dilutions of brain homogenates (BH) from a 263k infected hamster and from a patient with sCJD (MM1 subtype). We then compared the different standard decontamination procedures including partially and fully efficient treatments by detecting the residual seeding activity on 263K and sCJD contaminated wires. We completed our study by the evaluation of marketed reagents endorsed for prion decontamination.
Results:
The two amplification techniques can detect minute quantities of PrPTSE adsorbed onto a single wire. 8/8 wires contaminated with a 10-6 dilution of 263k BH and 1/6 with the 10-8 dilution are positive with Surf-PMCA. Similar performances were obtained with Surf-QuIC on 263K: 10/16 wires contaminated with 10-6 dilution and 1/8 wires contaminated with 10-8 dilution are positive. Regarding the human sCJD-MM1 prion, Surf-QuIC allows us to detect 16/16 wires contaminated with 10-6 dilutions and 14/16 with 10-7 . Results obtained after decontamination treatments are very similar between 263K and sCJD prions. Efficiency of marketed treatments to remove prions is lower than expected.
Conclusions:
Surf-PMCA and Surf-QuIC are very sensitive methods for the detection of prions on wires and could be applied to prion decontamination studies for rapid evaluation of new treatments. Sodium hypochlorite is the only product to efficiently remove seeding activity of both 263K and sCJD prions.
=====
WA2 Oral transmission of CWD into Cynomolgus macaques: signs of atypical disease, prion conversion and infectivity in macaques and bio-assayed transgenic mice
Schatzl HM (1, 2), Hannaoui S (1, 2), Cheng Y-C (1, 2), Gilch S (1, 2), Beekes M (3), SchulzSchaeffer W (4), Stahl-Hennig C (5) and Czub S (2, 6)
(1) University of Calgary, Calgary Prion Research Unit, Calgary, Canada (2) University of Calgary, Faculty of Veterinary Medicine, Calgary, Canada, (3) Robert Koch Institute, Berlin, Germany, (4) University of Homburg/Saar, Homburg, Germany, (5) German Primate Center, Goettingen, Germany, (6) Canadian Food Inspection Agency (CFIA), Lethbridge, Canada.
To date, BSE is the only example of interspecies transmission of an animal prion disease into humans. The potential zoonotic transmission of CWD is an alarming issue and was addressed by many groups using a variety of in vitro and in vivo experimental systems. Evidence from these studies indicated a substantial, if not absolute, species barrier, aligning with the absence of epidemiological evidence suggesting transmission into humans. Studies in non-human primates were not conclusive so far, with oral transmission into new-world monkeys and no transmission into old-world monkeys. Our consortium has challenged 18 Cynomolgus macaques with characterized CWD material, focusing on oral transmission with muscle tissue. Some macaques have orally received a total of 5 kg of muscle material over a period of 2 years. After 5-7 years of incubation time some animals showed clinical symptoms indicative of prion disease, and prion neuropathology and PrPSc deposition were found in spinal cord and brain of euthanized animals. PrPSc in immunoblot was weakly detected in some spinal cord materials and various tissues tested positive in RT-QuIC, including lymph node and spleen homogenates. To prove prion infectivity in the macaque tissues, we have intracerebrally inoculated 2 lines of transgenic mice, expressing either elk or human PrP. At least 3 TgElk mice, receiving tissues from 2 different macaques, showed clinical signs of a progressive prion disease and brains were positive in immunoblot and RT-QuIC. Tissues (brain, spinal cord and spleen) from these and preclinical mice are currently tested using various read-outs and by second passage in mice. Transgenic mice expressing human PrP were so far negative for clear clinical prion disease (some mice >300 days p.i.). In parallel, the same macaque materials are inoculated into bank voles. Taken together, there is strong evidence of transmissibility of CWD orally into macaques and from macaque tissues into transgenic mouse models, although with an incomplete attack rate. The clinical and pathological presentation in macaques was mostly atypical, with a strong emphasis on spinal cord pathology. Our ongoing studies will show whether the transmission of CWD into macaques and passage in transgenic mice represents a form of non-adaptive prion amplification, and whether macaque-adapted prions have the potential to infect mice expressing human PrP. The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD.
See also poster P103
***> The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD.
=====
WA16 Monitoring Potential CWD Transmission to Humans
Belay ED
Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases, Atlanta, GA, USA.
The spread of chronic wasting disease (CWD) in animals has raised concerns about increasing human exposure to the CWD agent via hunting and venison consumption, potentially facilitating CWD transmission to humans. Several studies have explored this possibility, including limited epidemiologic studies, in vitro experiments, and laboratory studies using various types of animal models. Most human exposures to the CWD agent in the United States would be expected to occur in association with deer and elk hunting in CWD-endemic areas. The Centers for Disease Control and Prevention (CDC) collaborated with state health departments in Colorado, Wisconsin, and Wyoming to identify persons at risk of CWD exposure and to monitor their vital status over time. Databases were established of persons who hunted in Colorado and Wyoming and those who reported consumption of venison from deer that later tested positive in Wisconsin. Information from the databases is periodically cross-checked with mortality data to determine the vital status and causes of death for deceased persons. Long-term follow-up of these hunters is needed to assess their risk of development of a prion disease linked to CWD exposure.
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P166 Characterization of CJD strain profiles in venison consumers and non-consumers from Alberta and Saskatchewan
Stephanie Booth (1,2), Lise Lamoureux (1), Debra Sorensen (1), Jennifer L. Myskiw (1,2), Megan Klassen (1,2), Michael Coulthart (3), Valerie Sim (4)
(1) Zoonotic Diseases and Special Pathogens, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg (2) Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg (3) Canadian CJD Surveillance System, Public Health Agency of Canada, Ottawa (4) Division of Neurology, Department of Medicine Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton.
Chronic wasting disease (CWD) is spreading rapidly through wild cervid populations in the Canadian provinces of Alberta and Saskatchewan. While this has implications for tourism and hunting, there is also concern over possible zoonotic transmission to humans who eat venison from infected deer. Whilst there is no evidence of any human cases of CWD to date, the Canadian CJD Surveillance System (CJDSS) in Canada is staying vigilant. When variant CJD occurred following exposure to BSE, the unique biochemical fingerprint of the pathologic PrP enabled a causal link to be confirmed. However, we cannot be sure what phenotype human CWD prions would present with, or indeed, whether this would be distinct from that see in sporadic CJD. Therefore we are undertaking a systematic analysis of the molecular diversity of CJD cases of individuals who resided in Alberta and Saskatchewan at their time of death comparing venison consumers and non-consumers, using a variety of clinical, imaging, pathological and biochemical markers. Our initial objective is to develop novel biochemical methodologies that will extend the baseline glycoform and genetic polymorphism typing that is already completed by the CJDSS. Firstly, we are reviewing MRI, EEG and pathology information from over 40 cases of CJD to select clinically affected areas for further investigation. Biochemical analysis will include assessment of the levels of protease sensitive and resistant prion protein, glycoform typing using 2D gel electrophoresis, testing seeding capabilities and kinetics of aggregation by quaking-induced conversion, and determining prion oligomer size distributions with asymmetric flow field fractionation with in-line light scattering. Progress and preliminary data will be presented. Ultimately, we intend to further define the relationship between PrP structure and disease phenotype and establish a baseline for the identification of future atypical CJD cases that may arise as a result of exposure to CWD.
=====
Source Prion Conference 2018 Abstracts
Volume 24, Number 8—August 2018 Research Susceptibility of Human Prion Protein to Conversion by Chronic Wasting Disease Prions
Marcelo A. BarriaComments to Author , Adriana Libori, Gordon Mitchell, and Mark W. Head Author affiliations: National CJD Research and Surveillance Unit, University of Edinburgh, Edinburgh, Scotland, UK (M.A. Barria, A. Libori, M.W. Head); National and OIE Reference Laboratory for Scrapie and CWD, Canadian Food Inspection Agency, Ottawa, Ontario, Canada (G. Mitchell)
Abstract Chronic wasting disease (CWD) is a contagious and fatal neurodegenerative disease and a serious animal health issue for deer and elk in North America. The identification of the first cases of CWD among free-ranging reindeer and moose in Europe brings back into focus the unresolved issue of whether CWD can be zoonotic like bovine spongiform encephalopathy. We used a cell-free seeded protein misfolding assay to determine whether CWD prions from elk, white-tailed deer, and reindeer in North America can convert the human prion protein to the disease-associated form. We found that prions can convert, but the efficiency of conversion is affected by polymorphic variation in the cervid and human prion protein genes. In view of the similarity of reindeer, elk, and white-tailed deer in North America to reindeer, red deer, and roe deer, respectively, in Europe, a more comprehensive and thorough assessment of the zoonotic potential of CWD might be warranted.
snip...
Discussion Characterization of the transmission properties of CWD and evaluation of their zoonotic potential are important for public health purposes. Given that CWD affects several members of the family Cervidae, it seems reasonable to consider whether the zoonotic potential of CWD prions could be affected by factors such as CWD strain, cervid species, geographic location, and Prnp–PRNP polymorphic variation. We have previously used an in vitro conversion assay (PMCA) to investigate the susceptibility of the human PrP to conversion to its disease-associated form by several animal prion diseases, including CWD (15,16,22). The sensitivity of our molecular model for the detection of zoonotic conversion depends on the combination of 1) the action of proteinase K to degrade the abundant human PrPC that constitutes the substrate while only N terminally truncating any human PrPres produced and 2) the presence of the 3F4 epitope on human but not cervid PrP. In effect, this degree of sensitivity means that any human PrPres formed during the PMCA reaction can be detected down to the limit of Western blot sensitivity. In contrast, if other antibodies that detect both cervid and human PrP are used, such as 6H4, then newly formed human PrPres must be detected as a measurable increase in PrPres over the amount remaining in the reaction product from the cervid seed. Although best known for the efficient amplification of prions in research and diagnostic contexts, the variation of the PMCA method employed in our study is optimized for the definitive detection of zoonotic reaction products of inherently inefficient conversion reactions conducted across species barriers. By using this system, we previously made and reported the novel observation that elk CWD prions could convert human PrPC from human brain and could also convert recombinant human PrPC expressed in transgenic mice and eukaryotic cell cultures (15).
A previous publication suggested that mule deer PrPSc was unable to convert humanized transgenic substrate in PMCA assays (23) and required a further step of in vitro conditioning in deer substrate PMCA before it was able to cross the deer–human molecular barrier (24). However, prions from other species, such as elk (15) and reindeer affected by CWD, appear to be compatible with the human protein in a single round of amplification (as shown in our study). These observations suggest that different deer species affected by CWD could present differing degrees of the olecular compatibility with the normal form of human PrP.
The contribution of the polymorphism at codon 129 of the human PrP gene has been extensively studied and is recognized as a risk factor for Creutzfeldt-Jakob disease (4). In cervids, the equivalent codon corresponds to the position 132 encoding methionine or leucine. This polymorphism in the elk gene has been shown to play an important role in CWD susceptibility (25,26). We have investigated the effect of this cervid Prnp polymorphism on the conversion of the humanized transgenic substrate according to the variation in the equivalent PRNP codon 129 polymorphism. Interestingly, only the homologs methionine homozygous seed–substrate reactions could readily convert the human PrP, whereas the heterozygous elk PrPSc was unable to do so, even though comparable amounts of PrPres were used to seed the reaction. In addition, we observed only low levels of human PrPres formation in the reactions seeded with the homozygous methionine (132 MM) and the heterozygous (132 ML) seeds incubated with the other 2 human polymorphic substrates (129 MV and 129 VV). The presence of the amino acid leucine at position 132 of the elk Prnp gene has been attributed to a lower degree of prion conversion compared with methionine on the basis of experiments in mice made transgenic for these polymorphic variants (26). Considering the differences observed for the amplification of the homozygous human methionine substrate by the 2 polymorphic elk seeds (MM and ML), reappraisal of the susceptibility of human PrPC by the full range of cervid polymorphic variants affected by CWD would be warranted.
In light of the recent identification of the first cases of CWD in Europe in a free-ranging reindeer (R. tarandus) in Norway (2), we also decided to evaluate the in vitro conversion potential of CWD in 2 experimentally infected reindeer (18). Formation of human PrPres was readily detectable after a single round of PMCA, and in all 3 humanized polymorphic substrates (MM, MV, and VV). This finding suggests that CWD prions from reindeer could be more compatible with human PrPC generally and might therefore present a greater risk for zoonosis than, for example, CWD prions from white-tailed deer. A more comprehensive comparison of CWD in the affected species, coupled with the polymorphic variations in the human and deer PRNP–Prnp genes, in vivo and in vitro, will be required before firm conclusions can be drawn. Analysis of the Prnp sequence of the CWD reindeer in Norway was reported to be identical to the specimens used in our study (2). This finding raises the possibility of a direct comparison of zoonotic potential between CWD acquired in the wild and that produced in a controlled laboratory setting. (Table).
The prion hypothesis proposes that direct molecular interaction between PrPSc and PrPC is necessary for conversion and prion replication. Accordingly, polymorphic variants of the PrP of host and agent might play a role in determining compatibility and potential zoonotic risk. In this study, we have examined the capacity of the human PrPC to support in vitro conversion by elk, white-tailed deer, and reindeer CWD PrPSc. Our data confirm that elk CWD prions can convert the human PrPC, at least in vitro, and show that the homologous PRNP polymorphisms at codon 129 and 132 in humans and cervids affect conversion efficiency. Other species affected by CWD, particularly caribou or reindeer, also seem able to convert the human PrP. It will be important to determine whether other polymorphic variants found in other CWD-affected Cervidae or perhaps other factors (17) exert similar effects on the ability to convert human PrP and thus affect their zoonotic potential.
Dr. Barria is a research scientist working at the National CJD Research and Surveillance Unit, University of Edinburgh. His research has focused on understanding the molecular basis of a group of fatal neurologic disorders called prion diseases.
Acknowledgments We thank Aru Balachandran for originally providing cervid brain tissues, Abigail Diack and Jean Manson for providing mouse brain tissue, and James Ironside for his critical reading of the manuscript at an early stage.
This report is independent research commissioned and funded by the United Kingdom’s Department of Health Policy Research Programme and the Government of Scotland. The views expressed in this publication are those of the authors and not necessarily those of the Department of Health or the Government of Scotland.
Author contributions: The study was conceived and designed by M.A.B. and M.W.H. The experiments were conducted by M.A.B. and A.L. Chronic wasting disease brain specimens were provided by G.M. The manuscript was written by M.A.B. and M.W.H. All authors contributed to the editing and revision of the manuscript.
Prion 2017 Conference Abstracts
First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques: a work in progress Stefanie Czub1, Walter Schulz-Schaeffer2, Christiane Stahl-Hennig3, Michael Beekes4, Hermann Schaetzl5 and Dirk Motzkus6 1
University of Calgary Faculty of Veterinary Medicine/Canadian Food Inspection Agency; 2Universitatsklinikum des Saarlandes und Medizinische Fakultat der Universitat des Saarlandes; 3 Deutsches Primaten Zentrum/Goettingen; 4 Robert-Koch-Institut Berlin; 5 University of Calgary Faculty of Veterinary Medicine; 6 presently: Boehringer Ingelheim Veterinary Research Center; previously: Deutsches Primaten Zentrum/Goettingen
This is a progress report of a project which started in 2009.
21 cynomolgus macaques were challenged with characterized CWD material from white-tailed deer (WTD) or elk by intracerebral (ic), oral, and skin exposure routes. Additional blood transfusion experiments are supposed to assess the CWD contamination risk of human blood product. Challenge materials originated from symptomatic cervids for ic, skin scarification and partially per oral routes (WTD brain). Challenge material for feeding of muscle derived from preclinical WTD and from preclinical macaques for blood transfusion experiments. We have confirmed that the CWD challenge material contained at least two different CWD agents (brain material) as well as CWD prions in muscle-associated nerves.
Here we present first data on a group of animals either challenged ic with steel wires or per orally and sacrificed with incubation times ranging from 4.5 to 6.9 years at postmortem. Three animals displayed signs of mild clinical disease, including anxiety, apathy, ataxia and/or tremor. In four animals wasting was observed, two of those had confirmed diabetes. All animals have variable signs of prion neuropathology in spinal cords and brains and by supersensitive IHC, reaction was detected in spinal cord segments of all animals. Protein misfolding cyclic amplification (PMCA), real-time quaking-induced conversion (RT-QuiC) and PET-blot assays to further substantiate these findings are on the way, as well as bioassays in bank voles and transgenic mice.
At present, a total of 10 animals are sacrificed and read-outs are ongoing. Preclinical incubation of the remaining macaques covers a range from 6.4 to 7.10 years. Based on the species barrier and an incubation time of > 5 years for BSE in macaques and about 10 years for scrapie in macaques, we expected an onset of clinical disease beyond 6 years post inoculation.
PRION 2017 DECIPHERING NEURODEGENERATIVE DISORDERS ABSTRACTS REFERENCE
8. Even though human TSE‐exposure risk through consumption of game from European cervids can be assumed to be minor, if at all existing, no final conclusion can be drawn due to the overall lack of scientific data. In particular the US data do not clearly exclude the possibility of human (sporadic or familial) TSE development due to consumption of venison. The Working Group thus recognizes a potential risk to consumers if a TSE would be present in European cervids. It might be prudent considering appropriate measures to reduce such a risk, e.g. excluding tissues such as CNS and lymphoid tissues from the human food chain, which would greatly reduce any potential risk for consumers. However, it is stressed that currently, no data regarding a risk of TSE infections from cervid products are available.
SATURDAY, FEBRUARY 23, 2019
Chronic Wasting Disease CWD TSE Prion and THE FEAST 2003 CDC an updated review of the science 2019
TUESDAY, NOVEMBER 04, 2014
Six-year follow-up of a point-source exposure to CWD contaminated venison in an Upstate New York community: risk behaviours and health outcomes 2005–2011
Authors, though, acknowledged the study was limited in geography and sample size and so it couldn't draw a conclusion about the risk to humans. They recommended more study. Dr. Ermias Belay was the report's principal author but he said New York and Oneida County officials are following the proper course by not launching a study. "There's really nothing to monitor presently. No one's sick," Belay said, noting the disease's incubation period in deer and elk is measured in years. "
Transmission Studies
Mule deer transmissions of CWD were by intracerebral inoculation and compared with natural cases {the following was written but with a single line marked through it ''first passage (by this route)}....TSS
resulted in a more rapidly progressive clinical disease with repeated episodes of synocopy ending in coma. One control animal became affected, it is believed through contamination of inoculum (?saline). Further CWD transmissions were carried out by Dick Marsh into ferret, mink and squirrel monkey. Transmission occurred in ALL of these species with the shortest incubation period in the ferret.
snip....
Prion Infectivity in Fat of Deer with Chronic Wasting Disease▿
Brent Race#, Kimberly Meade-White#, Richard Race and Bruce Chesebro* + Author Affiliations
In mice, prion infectivity was recently detected in fat. Since ruminant fat is consumed by humans and fed to animals, we determined infectivity titers in fat from two CWD-infected deer. Deer fat devoid of muscle contained low levels of CWD infectivity and might be a risk factor for prion infection of other species.
Prions in Skeletal Muscles of Deer with Chronic Wasting Disease
Here bioassays in transgenic mice expressing cervid prion protein revealed the presence of infectious prions in skeletal muscles of CWD-infected deer, demonstrating that humans consuming or handling meat from CWD-infected deer are at risk to prion exposure.
*** now, let’s see what the authors said about this casual link, personal communications years ago, and then the latest on the zoonotic potential from CWD to humans from the TOKYO PRION 2016 CONFERENCE.
see where it is stated NO STRONG evidence. so, does this mean there IS casual evidence ???? “Our conclusion stating that we found no strong evidence of CWD transmission to humans”
From: TSS
Subject: CWD aka MAD DEER/ELK TO HUMANS ???
Date: September 30, 2002 at 7:06 am PST
From: "Belay, Ermias"
To: Cc: "Race, Richard (NIH)" ; ; "Belay, Ermias"
Sent: Monday, September 30, 2002 9:22 AM
Subject: RE: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Dear Sir/Madam,
In the Archives of Neurology you quoted (the abstract of which was attached to your email), we did not say CWD in humans will present like variant CJD.. That assumption would be wrong. I encourage you to read the whole article and call me if you have questions or need more clarification (phone: 404-639-3091). Also, we do not claim that "no-one has ever been infected with prion disease from eating venison." Our conclusion stating that we found no strong evidence of CWD transmission to humans in the article you quoted or in any other forum is limited to the patients we investigated.
Ermias Belay, M.D. Centers for Disease Control and Prevention
-----Original Message-----
From: Sent: Sunday, September 29, 2002 10:15 AM
Subject: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Sunday, November 10, 2002 6:26 PM .......snip........end..............TSS
Thursday, April 03, 2008
A prion disease of cervids: Chronic wasting disease 2008 1: Vet Res. 2008 Apr 3;39(4):41 A prion disease of cervids: Chronic wasting disease Sigurdson CJ.
snip...
*** twenty-seven CJD patients who regularly consumed venison were reported to the Surveillance Center***,
snip... full text ;
> However, to date, no CWD infections have been reported in people.
sporadic, spontaneous CJD, 85%+ of all human TSE, did not just happen. never in scientific literature has this been proven.
if one looks up the word sporadic or spontaneous at pubmed, you will get a laundry list of disease that are classified in such a way;
sporadic = 54,983 hits https://www.ncbi.nlm.nih.gov/pubmed/?term=sporadic
spontaneous = 325,650 hits https://www.ncbi.nlm.nih.gov/pubmed/?term=spontaneous
key word here is 'reported'. science has shown that CWD in humans will look like sporadic CJD. SO, how can one assume that CWD has not already transmitted to humans? they can't, and it's as simple as that. from all recorded science to date, CWD has already transmitted to humans, and it's being misdiagnosed as sporadic CJD. ...terry
*** LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL THE WRONG PLACES $$$ ***
> However, to date, no CWD infections have been reported in people.
key word here is ‘reported’. science has shown that CWD in humans will look like sporadic CJD. SO, how can one assume that CWD has not already transmitted to humans? they can’t, and it’s as simple as that. from all recorded science to date, CWD has already transmitted to humans, and it’s being misdiagnosed as sporadic CJD. …terry
*** LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL THE WRONG PLACES $$$ ***
*** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).***
CWD TSE PRION AND ZOONOTIC, ZOONOSIS, POTENTIAL
Subject: Re: DEER SPONGIFORM ENCEPHALOPATHY SURVEY & HOUND STUDY
Date: Fri, 18 Oct 2002 23:12:22 +0100
From: Steve Dealler
Reply-To: Bovine Spongiform Encephalopathy Organization: Netscape Online member
To: BSE-L@ References:
Dear Terry,
An excellent piece of review as this literature is desperately difficult to get back from Government sites.
What happened with the deer was that an association between deer meat eating and sporadic CJD was found in about 1993. The evidence was not great but did not disappear after several years of asking CJD cases what they had eaten. I think that the work into deer disease largely stopped because it was not helpful to the UK industry...and no specific cases were reported. Well, if you dont look adequately like they are in USA currenly then you wont find any!
Steve Dealler ===============
''The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).''
CREUTZFELDT JAKOB DISEASE SURVEILLANCE IN THE UNITED KINGDOM THIRD ANNUAL REPORT AUGUST 1994
Consumption of venison and veal was much less widespread among both cases and controls. For both of these meats there was evidence of a trend with increasing frequency of consumption being associated with increasing risk of CJD. (not nvCJD, but sporadic CJD...tss) These associations were largely unchanged when attention was restricted to pairs with data obtained from relatives. ...
Table 9 presents the results of an analysis of these data.
There is STRONG evidence of an association between ‘’regular’’ veal eating and risk of CJD (p = .0.01).
Individuals reported to eat veal on average at least once a year appear to be at 13 TIMES THE RISK of individuals who have never eaten veal.
There is, however, a very wide confidence interval around this estimate. There is no strong evidence that eating veal less than once per year is associated with increased risk of CJD (p = 0.51).
The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).
There is some evidence that risk of CJD INCREASES WITH INCREASING FREQUENCY OF LAMB EATING (p = 0.02).
The evidence for such an association between beef eating and CJD is weaker (p = 0.14). When only controls for whom a relative was interviewed are included, this evidence becomes a little STRONGER (p = 0.08).
snip...
It was found that when veal was included in the model with another exposure, the association between veal and CJD remained statistically significant (p = < 0.05 for all exposures), while the other exposures ceased to be statistically significant (p = > 0.05).
snip...
In conclusion, an analysis of dietary histories revealed statistical associations between various meats/animal products and INCREASED RISK OF CJD. When some account was taken of possible confounding, the association between VEAL EATING AND RISK OF CJD EMERGED AS THE STRONGEST OF THESE ASSOCIATIONS STATISTICALLY. ...
snip...
In the study in the USA, a range of foodstuffs were associated with an increased risk of CJD, including liver consumption which was associated with an apparent SIX-FOLD INCREASE IN THE RISK OF CJD. By comparing the data from 3 studies in relation to this particular dietary factor, the risk of liver consumption became non-significant with an odds ratio of 1.2 (PERSONAL COMMUNICATION, PROFESSOR A. HOFMAN. ERASMUS UNIVERSITY, ROTTERDAM). (???...TSS)
snip...see full report ;
http://web.archive.org/web/20090506050043/http://www.bseinquiry.gov.uk/files/yb/1994/08/00004001.pdf
http://web.archive.org/web/20090506050007/http://www.bseinquiry.gov.uk/files/yb/1994/10/00003001.pdf
http://web.archive.org/web/20090506050244/http://www.bseinquiry.gov.uk/files/yb/1994/07/00001001.pdf
Stephen Dealler is a consultant medical microbiologist deal@airtime.co.uk
BSE Inquiry Steve Dealler
Management In Confidence
BSE: Private Submission of Bovine Brain Dealler
snip...see full text;
MONDAY, FEBRUARY 25, 2019
***> MAD DOGS AND ENGLISHMEN BSE, SCRAPIE, CWD, CJD, TSE PRION A REVIEW 2019
2004
Jeff Swann and his Mom, cwd link... sporadic CJD?, CBC NEWS Jeff Schwan sCJD, CWD, and Professor Aguzzi on BSE and sporadic CJD
????: CBCnews
2004
April 22, 2004, 10:30 AM CDT
Guests: Patrick Singh, Terry Schwan, Janet Skarbek, Bill Fielding
(BEGIN VIDEOTAPE)
ANNOUNCER: DEBORAH NORVILLE TONIGHT.
***> ''The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).''
***> In conclusion, sensory symptoms and loss of reflexes in Gerstmann-Sträussler-Scheinker syndrome can be explained by neuropathological changes in the spinal cord. We conclude that the sensory symptoms and loss of lower limb reflexes in Gerstmann-Sträussler-Scheinker syndrome is due to pathology in the caudal spinal cord. <***
***> The clinical and pathological presentation in macaques was mostly atypical, with a strong emphasis on spinal cord pathology.<***
***> The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD. <***
***> All animals have variable signs of prion neuropathology in spinal cords and brains and by supersensitive IHC, reaction was detected in spinal cord segments of all animals.<***
***> In particular the US data do not clearly exclude the possibility of human (sporadic or familial) TSE development due to consumption of venison. The Working Group thus recognizes a potential risk to consumers if a TSE would be present in European cervids.'' Scientific opinion on chronic wasting disease (II) <***
***Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.***
Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations
Emmanuel Comoy, Jacqueline Mikol, Valerie Durand, Sophie Luccantoni, Evelyne Correia, Nathalie Lescoutra, Capucine Dehen, and Jean-Philippe Deslys Atomic Energy Commission; Fontenay-aux-Roses, France
Prion diseases (PD) are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal PD might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, PD, like the other proteinopathies, are reputed to occur spontaneously (atpical animal prion strains, sporadic CJD summing 80% of human prion cases).
Non-human primate models provided the first evidences supporting the transmissibiity of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health (Chen, 2014), according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the zoonotic potential of other animal PD from bovine, ovine and cervid origins even after very long silent incubation periods.
*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,
***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),
***is the third potentially zoonotic PD (with BSE and L-type BSE),
***thus questioning the origin of human sporadic cases.
We will present an updated panorama of our different transmission studies and discuss the implications of such extended incubation periods on risk assessment of animal PD for human health.
===============
***thus questioning the origin of human sporadic cases***
===============
***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.
==============
PRION 2015 CONFERENCE
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
PRION 2016 TOKYO
Saturday, April 23, 2016
SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016
Prion. 10:S15-S21. 2016 ISSN: 1933-6896 printl 1933-690X online
Taylor & Francis
Prion 2016 Animal Prion Disease Workshop Abstracts
WS-01: Prion diseases in animals and zoonotic potential
Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
Title: Transmission of scrapie prions to primate after an extended silent incubation period)
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies
Location: Virus and Prion Research
Title: Transmission of the atypical/nor98 scrapie agent to suffolk sheep with VRQ/ARQ, ARQ/ARQ, and ARQ/ARR genotypes
Author item Cassmann, Eric item MAMMADOVA, JAJIBA - Orise Fellow item BENESTAD, SYLVIE - Norwegian Veterinary Institute item MOORE, SARA JO - Orise Fellow item Greenlee, Justin
Submitted to: PLoS ONE Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/21/2021 Publication Date: 2/11/2021
Citation: Cassmann, E.D., Mammadova, J., Benestad, S., Moore, S., Greenlee, J.J. 2021. Transmission of the atypical/nor98 scrapie agent to suffolk sheep with VRQ/ARQ, ARQ/ARQ, and ARQ/ARR genotypes. PLoS ONE. 16(2). Article e0246503. https://doi.org/10.1371/journal.pone.0246503. DOI: https://doi.org/10.1371/journal.pone.0246503
Interpretive Summary: Atypical scrapie is a prion disease that affects sheep. Unlike classical scrapie, atypical scrapie is thought to occur spontaneously, and it is unlikely to transmit between sheep under natural conditions. Another notable distinction between classical and atypical scrapie is the prion protein genotype of afflicted sheep and the locations in the brain where misfolded prions accumulate. Atypical scrapie generally occurs in sheep that are resistant to classical scrapie. Misfolded prions are predominantly found in the cerebellum for atypical scrapie and not in the brainstem as seen with classical scrapie. Atypical scrapie is a relevant disease because of its potential association with other prion diseases. Some research has shown that the atypical scrapie agent can undergo a transformation of disease forms that makes it appear like classical scrapie or classical bovine spongiform encephalopathy (mad cow disease). Therefore, atypical scrapie is thought to be a possible source for these prion diseases. We investigated the transmission of the atypical scrapie agent to sheep with three different prion protein genotypes. A diagnosis of atypical scrapie was made in all three genotypes of sheep. Misfolded prion protein was detected earliest in the cerebellum and the retina. This is the first report describing the early accumulation of misfolded prions in the retina of sheep with atypical scrapie. Understanding where misfolded prions accumulate in cases of atypical scrapie can lead to better detection earlier in the disease. Furthermore, the materials derived from this experiment will aid in investigating origins of other prion diseases.
Technical Abstract: Scrapie is a transmissible spongiform encephalopathy that occurs in sheep. Atypical/Nor98 scrapie occurs in sheep with that tend to be resistant to classical scrapie and it is thought to occur spontaneously. The purpose of this study was to test the transmission of the Atypical/Nor98 scrapie agent in three genotypes of Suffolk sheep and characterize the distribution of misfolded prion protein (PrPSc). Ten sheep were intracranially inoculated with brain homogenate from a sheep with Atypical/Nor98 scrapie. All sheep with the ARQ/ARQ and ARQ/ARR genotypes developed Atypical/Nor98 scrapie confirmed by immunohistochemistry, and one (1/3) sheep with the VRQ/ARQ genotype had detectable PrPSc consistent with Atypical/Nor98 scrapie at the experimental endpoint of 8 years. Sheep with mild early accumulations of PrPSc in the cerebellum had concomitant retinal PrPSc. Accordingly, large amounts of retinal PrPSc were identified in clinically affected sheep and sheep with dense accumulations of PrPSc in the cerebellum.
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research
Title: Scrapie in white-tailed deer: a strain of the CWD agent that efficiently transmits to sheep?
Author item Greenlee, Justin item KOKEMULLER, ROBYN - US Department Of Agriculture (USDA) item MOORE, S - Oak Ridge Institute For Science And Education (ORISE) item WEST GREENLEE, M - Iowa State University
Submitted to: Meeting Abstract Publication Type: Abstract Only Publication Acceptance Date: 3/29/2019 Publication Date: N/A Citation: N/A
Interpretive Summary:
Technical Abstract: Scrapie is a transmissible spongiform encephalopathy of sheep and goats that is associated with widespread accumulation of abnormal prion protein (PrPSc) in the central nervous and lymphoid tissues. Chronic wasting disease (CWD) is the natural prion disease of cervid species, and the tissue distribution of PrPSc in affected cervids is similar to scrapie in sheep. There are several lines of evidence that suggest that multiple strains of CWD exist, which may affect the agent’s potential to transmit to hosts of the same or different species. We inoculated white-tailed deer with the scrapie agent from ARQ/ARQ sheep, which resulted in 100% attack rates by either the intracranial or oronasal route of inoculation. When examining tissues from the brainstems or lymphoid tissues by traditional diagnostic methods such as immunohistochemistry or western blots, it is difficult to differentiate tissues from deer infected with scrapie from those infected with CWD. However, there are several important differences between tissues from scrapie-infected white-tailed deer (WTD scrapie) and those infected with CWD (WTD CWD). First, there are different patterns of PrPSc deposition in the brains of infected deer: brain tissues from deer with WTD scrapie had predominantly particulate and stellate immunoreactivity whereas those from deer with WTD-CWD had large aggregates and plaque-like staining. Secondly, the incubation periods of WTD scrapie isolates are longer than CWD isolates in mice expressing cervid prion protein. Most notably, the transmission potential of these two isolates back to sheep is distinctly different. Attempts to transmit various CWD isolates to sheep by the oral or oronasal routes have been unsuccessful despite observation periods of up to 7 years. However, WTD scrapie efficiently transmitted back to sheep by the oronasal route. Upon transmission back to sheep, the WTD scrapie isolate exhibited different phenotypic properties when compared to the sheep receiving the original sheep scrapie inoculum including different genotype susceptibilities, distinct PrPSc deposition patterns, and much more rapid incubation periods in transgenic mice expressing the ovine prion protein. The scrapie agent readily transmits between sheep and deer after oronasal exposure. This could confound the identication of CWD strains in deer and the eradication of scrapie from sheep.
''The scrapie agent readily transmits between sheep and deer after oronasal exposure. This could confound the identication of CWD strains in deer and the eradication of scrapie from sheep.''
RT-QuIC detection of pathological prion protein in subclinical goats following experimental oral transmission of L-type BSE
Alessandra Favole1* , Maria Mazza1 , Antonio D’Angelo2 , Guerino Lombardi3 , Claudia Palmitessa1 , Luana Dell’Atti1 , Giulia Cagnotti2 , Elena Berrone1 , Marina Gallo1 , Tiziana Avanzato1 , Erika Messana1 , Loretta Masoero1 , Pier Luigi Acutis1 , Daniela Meloni1 , Franco Cardone4 , Maria Caramelli1 , Cristina Casalone1 and Cristiano Corona1*
Abstract
Objective: The spread of bovine spongiform encephalopathy (BSE) agent to small ruminants is still a major issue in the surveillance of transmissible spongiform encephalopathies (TSEs). L-type bovine spongiform encephalopathy (L-BSE) is an atypical form of BSE with an unknown zoonotic potential that is transmissible to cattle and small ruminants. Our current knowledge of bovine atypical prion strains in sheep and goat relies only on experimental transmission studies by intracranial inoculation. To assess oral susceptibility of goats to L-BSE, we orally inoculated five goats with cattle L-BSE brain homogenates and investigated pathogenic prion protein (PrPsc) distribution by an ultrasensitive in vitro conversion assay known as Real-Time Quaking Induced Conversion (RT-QuIC).
Results: Despite a prolonged observation period of 80 months, all these animals and the uninfected controls did not develop clinical signs referable to TSEs and tested negative by standard diagnostics. Otherwise, RT-QuIC analysis showed seeding activity in five out of five examined brain samples. PrPsc accumulation was also detected in spinal cord and lymphoreticular system. These results indicate that caprine species are susceptible to L-BSE by oral transmission and that ultrasensitive prion tests deserve consideration to improve the potential of current surveillance systems against otherwise undetectable forms of animal prion infections.
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Discussion and conclusions
Data here presented indicate that caprine species are susceptible to L-BSE after oral administration and are able to produce very low levels of prions in both lymphatic and central nervous tissues as demonstrated by optimized, high-sensitive, RT-QuIC assay.
At variance with goats intracerebrally infected with L-BSE [4], in this study, no animal developed clinical signs of disease despite prolonged periods of observation, suggesting a comparatively low efficiency of the oral route versus the intracerebral one in L-BSE, a feature that further distinguish this strain from classical BSE [14, 15].
Interestingly, all goats tested negative by standard diagnostics for PrPsc performed on brainstem. This finding, associated with the low amount of PrPsc detected in different brain areas, suggests a partial strain-specific transmission barrier. Indeed, inoculation of a prion into a new host species can produce prolonged incubation periods and/or subclinical infection [16, 17]. In addition, the lack of clinical signs suggests that naturally L-BSE-infected goats may be asymptomatic similarly to what proposed by Okada et al. for oral L-BSE in cattle [17].
In line with previous results [18], RT-QuIC detected lower levels of prions than traditional diagnostic tools. Rapid and confirmatory tests failed to identify any PrPsc in the subclinical animals, while RT-QuIC allowed us to detect misfolded prion protein in multiple brain regions, spinal cord and lymphoreticular system. Studies have established that the rate of fluorescence increase in RTQuIC, while not measuring infectivity, is directly related to the concentration of prions in the sample seeding the reaction [19, 20]. Prolonged lag phases of RT-QuIC reactions indicate relatively low amounts of PrPsc in the examined tissues and may reassure about the possibility of goat to play as silent L-BSE spreaders in natural conditions. However, we believe that prudence must be always adopted when dealing with the risk of prion spread in field conditions as also suggested by recent data by Denkers and colleagues, who showed that the oral route of infection for chronic wasting disease in deer, may be much more efficient than previously thought [21]. Furthermore, although the mere presence of PrPsc is not indicative of a possible infectivity of the tissue, the finding of positivity in the lymphoreticular tissue must alert to the potential distribution of PrPsc in peripheral body regions which may increase the risks for humans. Bioassay of infectivity by inoculation of susceptible animals with brains of these goats may help to clarify this issue.
Based on the results achieved with this prion form and also other animal strains, it would be useful to consider the possibility to enlarge current diagnostic criteria to include, in defined conditions (e.g. very limited amounts of source tissue, or preclinical testing), the application of ultrasensitive diagnostic methods. This will not only improve the sensitivity of our surveillance systems but will also help to protect food chain from accidental spillovers of the agent of L-BSE.
Limitations
Te primary limitation of this work is that infectivity was not demonstrated by bioassay and the infectious titre was not determined. Terefore, we cannot comment the degree of risk for human.
Despite these limitations, this work specifcally demonstrates prion-seeding activity in tissues of goats orally exposed to L-BSE and provide RT-QuIC as useful method to enhance surveillance of TSEs.
Keywords: Prion, L-BSE, RT-QuIC, Goat, Oral transmission, PrPsc, Ultrasensitive detection
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TUESDAY, NOVEMBER 29, 2022
Texas CWD Confirmed High Fence Release Site Kaufman County, To Date 420 Cases Confirmed
THURSDAY, NOVEMBER 24, 2022
Ohio 3 positive CWD cases confirmed this fall 2 Wyandot and 1 Marion Counties
FRIDAY, NOVEMBER 18, 2022
Wisconsin Lincoln County Deer Farm Confirmed with CWD
SEE CWD BY STATE;
TUESDAY, NOVEMBER 29, 2022
CHRONIC WASTING DISEASE DETECTION AND MANAGEMENT: WHAT HAS WORKED AND WHAT HAS NOT?
Control of Chronic Wasting Disease OMB Control Number: 0579-0189 APHIS-2021-0004 Singeltary Submission
Docket No. APHIS-2018-0011 Chronic Wasting Disease Herd Certification
APHIS Indemnity Regulations [Docket No. APHIS-2021-0010] RIN 0579-AE65 Singeltary Comment SubmissionComment from Singeltary Sr., Terry
Posted by the Animal and Plant Health Inspection Service on Sep 8, 2022
Scrapie Field Trial was developed at Mission, Texas, on 450 acres of pastureland, part of the former Moore Air Force Base
EPIDEMIOLOGY OF SCRAPIE IN THE UNITED STATES
Academic Preg
James Hourriganl, Albert Klingsporn2, Edited by » Peast
W. W. Clark3, and M, de Camp4
United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services
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METHODS
A Scrapie Field Trial was developed at Mission, Texas, to provide additional information for the eradication program on the epidemiology of natural scrapie. The Mission Field Trial Station is located on 450 acres of pastureland, part of the former Moore Air Force Base, near Mission,
Texas. It was designed to bring previously exposed, and later also unexposed, sheep or goats to the Station and maintain and breed them under close observation for extended periods
to determine which animals would develop scrapie and define more closely the natural spread and other epidemiological aspects of the disease.
The 547 previously exposed sheep brought to the Mission Station beginning in 1964 were of the Cheviot, Hampshire, Montadale, or Suffolk breeds. They were purchased as field outbreaks occurred, and represented 21 bloodlines in which scrapie had been diagnosed. Upon arrival at the Station, the sheep were maintained on pasture, with supplemental feeding as necessary. The station was divided into 2 areas:
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RESULTS
Table 1 indicated that previously exposed sheep brought to the Station at various times and ages (1 to 89 months old) included 333 Suffolks at risk. Of these, 98 (29%) developed scrapie. This demonstrated the necessity to slaughter such sheep to prevent further Spread of the disease, These pre- viously exposed Suffolks were bred at the Station and produced 446 progeny at risk. Of these 153 (34%) developed scrapie.
Although the minimum and average ages when scnapied were similar for both groups, some of the previously exposed Suffolks brought to the Station developed scrapie when much older--ewes 60 to 142 months old and rams 67 to 102 months old. O£ the 153 Suffolks born at the Station, only 3 were more than 60 months of age (65, 66, and 69 months old).
This difference in age scrapied was attributed to the fact that the Suffolks born at the Station may have been sub- ject to a greater exposure from birth.
It was also observed that when both dam and progeny were scrapied, the progeny nearly always developed clinical disease at a younger age than their respective dam. Thirty- two dams were scrapied at an average of 60 months of age. Forty-six of their progeny developed the disease at an average of 38 months (range 25 to 53 months). Thirty-seven of the 46 progeny were younger than the dam (average 20 months younger, range 2 to 99 months younger). Two were scrapied at the same age as their dams, and 8 were older (average 5 months, range 1 to 13 months older).
++. Although the incidence of scrapie was considerably Greater in the progeny of scrapied compared to free dams, the progeny of either scrapied or free dams manifested scrapie at the typical age and irrespective of the age their respective dams were scrapied. The differences in ages that dams and progeny were scrapied was believed due to difference of exposure, particularly whether they were exposed at an early age,
Table 2 summarized the data on exposed Suffolks and was Prepared so as to show scrapie incidence in the progeny of dams and sires of known Scrapie status. The scrapie incidence in the progeny of Free X Free parents was 25%, progeny of scrapied Sires 39%, and scrapied dams 42%. When both sire and dam were scrapied, the scrapie incidence in 18 Progeny at risk was 78%.
When the scrapie status of the sire was ignored, scrapie incidence in th- progeny of free dams was 34% and in pre y of scrapied da as 62%. When the scrapie status of the dam was ignored, scrapie incidence in the progeny of free sires was 26% and in the progeny of scrapied sires was 452.
Although the scrapie incidence was nearly double in the progeny of scrapied compared to free dams, the latter con- tributed a greater number of scrapied progeny, 116, compared to only 51 cases which had scrapied dams. This was because free dams made a considerably heavier contribution to the progeny at risk4-342 compared to 82. It was felt that in farm flocks a similar situation could exist.
It was possible that free dams could have been mis- classified; however, this was unlikely to have been significant, unless "nonclinical or carrier" dams exist. In this Suffolk group, the ages of 100 free dams of scrapied progeny ranged from 25 to 160 (average 97) months. These free dams did not show clinical signs of scrapie,”and there were no histopathological lesions suggesting scrapie in those which died, If one cannot classify as free, ewes which have reached 97 months (average) and did not develop the disease, from a practical standpoint, it is not possible to classify sheep as free, at least on the basis of clinical signs and histology. The free dams of 50% of the scrapied progeny were more than 100 months of age, averaging 126 months.
Upon arrival at the Mission Station at 3 to 9 months of age, the 140 previously unexposed sheep and goats were placed in infected pastures and corrals and were subjected to con- tact with a succession of natural cases of scrapie in sheep, and eventually also in goats. These animals were bred only within their respective groups and were not crossbred to other breeds of sheep or those brought to the Station from infected flocks or their progeny. The male or female animals mixed freely with animals of their respective sex of the infected Flock and were similarly identified and subjected to similar flock management and diagnostic procedures.
Table 3 indicated that natural scrapie had occurred in 5 of the 140 previously unexposed sheep. One case each occurred in Rambouillet, Targhee, and Hampshire ewes at 88, 89, and 89 months of age and in % Suffolk ewes at 73 and 102 months of age, and 85, 82, 80, 64, and 93 months following initial natural exposure. This represented a natural situation involving lateral spread, under the circumstances involved, when sheep were not exposed when very young. Scrapie was not detected clinicaliy or histologically in any of the dairy or Angora goats brought to the Station. The disease occurred in an average of 27% of the progeny of previously unexposed sheep or goats born at the Station and included cases in progeny of all breeds of sheep or goats taken there, The incidence in the progeny ranged from 14% in Rambouillet sheep to 61% in dairy goats. ~
These data showed that scrapie spread laterally, by contact exposure, from scrapied te previously free animals, but at an apparently lower rate when exposure was first received at the age of 3 to 9 months. These animals were presumed to be susceptible to the disease, as their progeny developed scrapie at rates and ages similar (on the average) to the progeny, pf previously exposed Suffolk sheep born and reared in the same environment.
It was suggested that the progeny of previously unexposed animals developed scrapie at a much higher rate than their parents, and at a younger age, because they were subjected to exposure from birth. The data did not rule out the possibility that the animals born at the Station could have also received the virus from their dams "vertically" prior te, at, or following birth.
Table 4 summarized the scrapie incidence in #he progeny, born at the Station, of previously unexposed dairy goats.
The data were prepared so as to show scrapie incidence in the progeny of dams and sires of known scrapie status.
The 58% incidence in the progeny (24 at risk) of Free X Free parents was more than twice the 25% seen in the Suffolk group (Table 2). Scrapied sires did not increase the incidence in goat progeny (it was 44%); scrapied dams increased the incidence to 71%. When both sire and dam were scrapied the incidence was 89%, with only 9 goat progeny at risk.
When the scrapie status of the sire was ignored, the scrapie incidence in the progeny of free dams was 56% and in the progeny of scrapied dams it was 74%.
Free dams contributed 34 progeny at risk and scrapied dams 31 progeny.
When the scrapie status of the dam was ignored, scrapie incidence was 64% in the progeny of free sires and a similar 66% in the progeny of scrapied sires.
A total of 244 sheep (127 Suffolk, 59 Rambouillet, and 58 Targhee) were removed from scrapie exposure within a few hours of birth or at 4, 9, or 20 months of age and placed in isolation pens. Removal of sheep from exposure at these ages was selected as being representative of usual flock operations when sheep might be sold from an infected flock at weaning, the first fall or the second fall after their birth.
Table 5 reflected the fate of such animals. Four of the 6 scrapied sheep which had been isolated at birth were Suffolks and the 2 older animals were Targhees. The first case in the group isolated at birth was a Targhee, progeny of a ewe that did not develop clinical scrapie. The scrapie incidence in 36 at risk Suffolks removed from exposure at birth was 11%, con- siderably less -“en that expected had these animals remz d in an infected en ment.
Table 6 reflected the status of 51 goats isolated from scrapie exposure at birth, and at 6, 8 to 10, 20, 32 to 59 and 60 to 82 months of age.
None of the goats removed at birth developed scrapie, although all 5 of those alive at 5 years of age had scrapied dams and 1 also had a scrapied sire. The sire of the remaining 4 had sired 7 scrapied progeny. Under such circumstances, had they remained in an infected environment nearly all of these goats would have been expected to develop scrapie. With the exception of the 20 month group, scrapie occurred at an incidence of 25 to 100% in ali other groups and at the expected age. A further observation was that 4 of the progeny of these dairy goats, born and kept apart from any sheep, developed scrapie which suggested that goats were not "dead- end hosts" insofar as scrapie was concerned.
Table 7 recorded the fate of progeny of certain selected scrapied or free Suffolk sheep or dairy goat dams.’
Suffolk ewe G298 was scrapied at 46 months of age. She had twin lambs in 1969 and 1 lamb in 1970. All 3 lambs developed scrapie. Suffolk ewe G27a was scrapied at 39 months. Her lamb born in 1966 was scrapied at 53 months; however, her lambs born in 1967 and 1968 remained free--lived to 102 months of age.
Suffolk ewe G25a died at 131] months of age and was nega- tive clinically and histologically. Mice remained negative following intracerebral inoculation of brain, spleen, and lymph nodes from this ewe. This ewe had 9 progeny at risk, of which 4 developed scrapie and 5 did not. There was no dis- cernible pattern to the cases. In two instances, 1 twin was scrapied and 1 remained free.
Goat B259 was scrapied when 43 months old. All of her 6 progeny at risk developed scrapie.
Goat B14a remained free and died at 101 months of age. Of her 11 progeny at risk, 7 were scrapied and 4 were not.
It was observed at the Station that when scrapied dams had several progeny at risk, 1 or more progeny usually developed the disease. However, many such scrapied dams also had progeny which lived, or are living, considerably beyond the age of their dams and beyond the age animals born at the Station manifested the disease.
It was also observed that individual free dams had free progeny in earlier years followed by scrapied progeny when they were older, or had scrapied progeny when young followed by free progeny when older, or scrapie and free progeny dis- persed throughout the dam's breeding life. The same situation occurred in progeny of scrapied dams; however, the pattern was less irregular due to the smaller number of progeny from each scrapied dam and the higher incidence of scrapie in such progeny. Circumstances prevented breeding all ewes ary year and, thus, many had only 1 progeny at risk. Scrapie developed in 100% of the single progeny at risk of 11 scrapied and 15 free dams. The 26 scrapied progeny were equally divided between ewes and rams.
Table 8 reflected the difference in age scrapied of - sheep brought to the Station compared to the age scrapied of those born there. Although the average age of previously exposed sheep (Suffolks) brought to the Station did not differ greatly from the overall average, several animals brought to the Station developed the disease at quite advanced ages. The previously unexposed scrapied animals brought to the Station were also considerably older than animals born there. Progeny of scrapied dams developed the disease at a slightly younger age than did progeny of free dams. The average age was nearly the same for males and females.
DISCUSSION
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Tuesday, May 31, 2022
89th General Session of the World Assembly of OIE Delegates image for WOAH General Summit 2022 Chronic Wasting Disease CWD TSE Prion Discussions and Concerns
FRIDAY, NOVEMBER 25, 2022
USA National Scrapie Eradication Program (NSEP) 2021 to 2003 A Year by Year Review
WEDNESDAY, MARCH 16, 2022
SHEEP BY-PRODUCTS AND WHAT ABOUT Scrapie TSE PrP and Potential Zoonosis?
IBNC Tauopathy or TSE Prion disease, it appears, no one is sure
Terry S. Singeltary Sr., 03 Jul 2015 at 16:53 GMT
PLOS ONE Journal
IBNC Tauopathy or TSE Prion disease, it appears, no one is sure
Terry S. Singeltary Sr., 03 Jul 2015 at 16:53 GMT
***however in 1 C-type challenged animal, Prion 2015 Poster Abstracts S67 PrPsc was not detected using rapid tests for BSE.
***Subsequent testing resulted in the detection of pathologic lesion in unusual brain location and PrPsc detection by PMCA only.
*** IBNC Tauopathy or TSE Prion disease, it appears, no one is sure ***
WEDNESDAY, DECEMBER 23, 2020
Idiopathic Brainstem Neuronal Chromatolysis IBNC BSE TSE Prion a Review 2020
Monday, November 14, 2022
Prion Diseases in Dromedary Camels (CPD) 2022 Review
Tuesday, April 27, 2021
Working Document on Camel Prion Disease (CPrD) 14/09/2020
SATURDAY, SEPTEMBER 24, 2022
Transmission of CH1641 in cattle
WEDNESDAY, DECEMBER 8, 2021
Importation of Sheep, Goats, and Certain Other Ruminants AGENCY: Animal APHIA, USDA, FINAL RULE [Docket No. APHIS–2009–0095] RIN 0579–AD10
WEDNESDAY, MARCH 24, 2021
USDA Animal and Plant Health Inspection Service 2020 IMPACT REPORT BSE TSE Prion Testing and Surveillance MIA
https://animalhealthreportpriontse.blogspot.com/2021/03/usda-animal-and-plant-health-inspection.html
SUNDAY, MARCH 21, 2021
Investigation Results of Texas Cow That Tested Positive for Bovine Spongiform Encephalopathy (BSE) Aug. 30, 2005 Singeltary's Regiew 2021
FRIDAY, APRIL 1, 2022
USDA TAKES THE C OUT OF COOL, what's up with that?
THURSDAY, AUGUST 20, 2020
Why is USDA "only" BSE TSE Prion testing 25,000 samples a year?
THURSDAY, JANUARY 23, 2020
USDA Consolidates Regulations for NAHLN Laboratory Testing USDA Animal and Plant Health Inspection Service
sent this bulletin at 01/23/2020 02:15 PM EST
WEDNESDAY, APRIL 24, 2019
USDA Announces Atypical Bovine Spongiform Encephalopathy Detection Aug 29, 2018 A Review of Science 2019
Saturday, July 23, 2016
BOVINE SPONGIFORM ENCEPHALOPATHY BSE TSE PRION SURVEILLANCE, TESTING, AND SRM REMOVAL UNITED STATE OF AMERICA UPDATE JULY 2016
Tuesday, July 26, 2016
Atypical Bovine Spongiform Encephalopathy BSE TSE Prion UPDATE JULY 2016
Monday, June 20, 2016
Specified Risk Materials SRMs BSE TSE Prion Program
*** PLEASE SEE THIS URGENT UPDATE ON CWD AND FEED ANIMAL PROTEIN ***
Sunday, March 20, 2016
Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed ***UPDATED MARCH 2016*** Singeltary Submission
SEE MAD COW FEED VIOLATIONS AFER MAD COW FEED VIOLATIONS ;
Tuesday, April 19, 2016
Docket No. FDA-2013-N-0764 for Animal Feed Regulatory Program Standards Singeltary Comment Submission
17 years post mad cow feed ban August 1997
Monday, October 26, 2015
FDA PART 589 -- SUBSTANCES PROHIBITED FROM USE IN ANIMAL FOOD OR FEED VIOLATIONS OFFICIAL ACTION INDICATED OIA UPDATE October 2015
Tuesday, December 23, 2014
FDA PART 589 -- SUBSTANCES PROHIBITED FROM USE IN ANIMAL FOOD OR FEEDVIOLATIONS OFFICIAL ACTION INDICATED OAI UPDATE DECEMBER 2014 BSE TSE PRION
16 years post mad cow feed ban August 1997 2013
Sunday, December 15, 2013
FDA PART 589 -- SUBSTANCES PROHIBITED FROM USE IN ANIMAL FOOD OR FEED VIOLATIONS OFFICIAL ACTION INDICATED OIA UPDATE DECEMBER 2013 UPDATE
Saturday, August 29, 2009
FOIA REQUEST FEED RECALL 2009 Product may have contained prohibited materials Bulk Whole Barley, Recall # V-256-2009
Friday, September 4, 2009
FOIA REQUEST ON FEED RECALL PRODUCT 429,128 lbs. feed for ruminant animals may have been contaminated with prohibited material Recall # V-258-2009
Thursday, March 19, 2009
MILLIONS AND MILLIONS OF POUNDS OF MAD COW FEED IN COMMERCE USA WITH ONGOING 12 YEARS OF DENIAL NOW, WHY IN THE WORLD DO WE TO TALK ABOUT THIS ANYMORE $$$
MONDAY, FEBRUARY 25, 2019
***> MAD DOGS AND ENGLISHMEN BSE, SCRAPIE, CWD, CJD, TSE PRION A REVIEW 2019
SATURDAY, OCTOBER 8, 2022
Cattle with the EK211 PRNP polymorphism are susceptible to the H-type bovine spongiform encephalopathy agent from either E211K or wild type donors after oronasal inoculation
TUESDAY, NOVEMBER 01, 2022
SEAC Position statement Chronic wasting disease in UK deer January 2005 (updated July 2006) to 2021
TUESDAY, NOVEMBER 1, 2022
SEAC Scientific Steering Committee on TSE Prion
SATURDAY, NOVEMBER 5, 2022
EFSA Network on BSE-TSE Minutes of the 17th meeting Held on 13-14 October 2022
WEDNESDAY, JANUARY 12, 2022
Bovine Spongiform Encephalopathy BSE TSE Prion Origin USA, what if?
THURSDAY, OCTOBER 22, 2015
Former Ag Secretary Ann Veneman talks women in agriculture and we talk mad cow disease USDA and what really happened
THURSDAY, FEBRUARY 23, 2012
EIGHT FORMER SECRETARIES OF AGRICULTURE SPEAKING AT USDA'S 2012 AGRICULTURE OUTLOOK FORUM INDUCTED INTO USA MAD COW HALL OF SHAME
2020 DECEMBER
WEDNESDAY, DECEMBER 9, 2020
Biden's pick Tom Vilsack Failed Terribly on Mad Cow BSE TSE Prion, why put him back as top Agriculture pick?
SPONGIFORM ENCEPHALOPATHY ADVISORY COMMITTEE
Minutes of the 99th meeting held on 14th December 2007
snip...
ITEM 8 – PUBLIC QUESTION AND ANSWER SESSION 40.
The Chair explained that the purpose of the question and answer session was to give members of the public an opportunity to ask questions related to the work of SEAC. Mr Terry Singeltary (Texas, USA) had submitted a question prior to the meeting, asking: “With the Nor-98 now documented in five different states so far in the USA in 2007, and with the two atypical BSE H-base cases in Texas and Alabama, with both scrapie and chronic 14 © SEAC 2007 wasting disease (CWD) running rampant in the USA, is there any concern from SEAC with the rise of sporadic CJD in the USA from ''unknown phenotype'', and what concerns if any, in relations to blood donations, surgery, optical, and dental treatment, do you have with these unknown atypical phenotypes in both humans and animals in the USA? Does it concern SEAC, or is it of no concern to SEAC? Should it concern USA animal and human health officials?” 41.
A member considered that this question appeared to be primarily related to possible links between animal and human TSEs in the USA.
There is no evidence that sCJD is increasing in the USA and no evidence of any direct link between TSEs and CJD in the USA. Current evidence does not suggest that CWD is a significant risk to human health. There are unpublished data from a case of human TSE in the USA that are suggestive of an apparently novel form of prion disease with distinct molecular characteristics. However, it is unclear whether the case had been further characterised, if it could be linked to animal TSEs or if other similar cases had been found in the USA or elsewhere. In relation to the possible public health implications of atypical scrapie, H-type BSE and CWD, research was being conducted to investigate possible links and surveillance was in place to detect any changes in human TSEs. Although possible links between these diseases and human TSEs are of concern and require research, there is no evidence to suggest immediate public health action is warranted. The possible human health risks from classical scrapie had been discussed earlier in the meeting. Members noted that there are effective channels of discussion and collaboration on research between USA and European groups. Members agreed it is important to keep a watching brief on new developments on TSEs.
snip...
>>>There is no evidence that sCJD is increasing in the USA and no evidence of any direct link between TSEs and CJD in the USA.<<<
TUESDAY, APRIL 05, 2022 2022
American Academy of Neurology Emerging Sciences
Abstract Website
Incidence of Creutzfeldt-Jakob Disease in the United States 1993-2014
https://creutzfeldt-jakob-disease.blogspot.com/2022/04/incidence-of-creutzfeldt-jakob-disease_5.html
TUESDAY, MAY 24, 2022
Texas Creutzfeldt Jakob Disease CJD TSE Prion Update Singeltary FOIA Request Received May 23, 2022
MONDAY, JUNE 14, 2021
Texas Health and Human Services The Department of State Health Services Creutzfeldt Jakob Disease TSE Prion Report 2021?
SUNDAY, MAY 08, 2022
USA National Prion Disease Pathology Surveillance Center Surveillance Update April 11th, 2022
THURSDAY, JUNE 23, 2022
UK Research and analysis Creutzfeldt-Jakob disease (CJD) update (data to end of December 2021) Updated 21 June 2022
TUESDAY, MAY 10, 2022 Concordance of CSF RT-QuIC across the European Creutzfeldt-Jakob Disease surveillance network https://creutzfeldt-jakob-disease.blogspot.com/2022/05/concordance-of-csf-rt-quic-across.htmlTUESDAY, OCTOBER 18, 2022Assessing the Potential Transmissibility of Bovine and Cervid Prions with a Human Prion Protein-based Model ARS RESEARCHDiagnosis and Reporting of Creutzfeldt-Jakob DiseaseSingeltary, Sr et al. JAMA.2001; 285: 733-734. Vol. 285 No. 6, February 14, 2001 JAMA Diagnosis and Reporting of Creutzfeldt-Jakob Disease To the Editor: In their Research Letter, Dr Gibbons and colleagues1 reported that the annual US death rate due to Creutzfeldt-Jakob disease (CJD) has been stable since 1985. These estimates, however, are based only on reported cases, and do not include misdiagnosed or preclinical cases. It seems to me that misdiagnosis alone would drastically change these figures. An unknown number of persons with a diagnosis of Alzheimer disease in fact may have CJD, although only a small number of these patients receive the postmortem examination necessary to make this diagnosis. Furthermore, only a few states have made CJD reportable. Human and animal transmissible spongiform encephalopathies should be reportable nationwide and internationally.. Terry S. Singeltary, Sr Bacliff, Tex 1. Gibbons RV, Holman RC, Belay ED, Schonberger LB. Creutzfeldt-Jakob disease in the United States: 1979-1998. JAMA. 2000;284:2322-2323.http://jama.jamanetwork.com/article.aspx?articleid=1031186Elsevier Editorial System(tm) for The Lancet Infectious DiseasesManuscript DraftManuscript Number:Title: HUMAN and ANIMAL TSE Classifications i.e. mad cow disease and the UKBSEnvCJD only theoryArticle Type: Personal ViewCorresponding Author: Mr. Terry S. Singeltary,Corresponding Author's Institution: naFirst Author: Terry S Singeltary, noneOrder of Authors: Terry S Singeltary, none; Terry S. SingeltaryAbstract: TSEs have been rampant in the USA for decades in many species, and they all have been rendered and fed back to animals for human/animal consumption. I propose that the current diagnostic criteria for human TSEs only enhances and helps the spreading of human TSE from the continued belief of the UKBSEnvCJD only theory in 2007.HUMAN and ANIMAL TSE Classifications i.e. mad cow disease and the UKBSEnvCJD only theory August 2007August 2007HUMAN and ANIMAL TSE Classifications i.e. mad cow disease and the UKBSEnvCJD only theoryTSEs have been rampant in the USA for decades in many species, and they all have been rendered and fed back to animals for human/animal consumption. I propose that the current diagnostic criteria for human TSEs only enhances and helps the spreading of human TSE from the continued belief of the UKBSEnvCJD only theory in 2007. With all the science to date refuting it, to continue to validate this myth, will only spread this TSE agent through a multitude of potential routes and sources i.e. consumption, surgical, blood, medical, cosmetics etc. I propose as with Aguzzi, Asante, Collinge, Caughey, Deslys, Dormont, Gibbs, Ironside, Manuelidis, Marsh, et al and many more, that the world of TSE Transmissible Spongiform Encephalopathy is far from an exact science, but there is enough proven science to date that this myth should be put to rest once and for all, and that we move forward with a new classification for human and animal TSE that would properly identify the infected species, the source species, and then the route.This would further have to be broken down to strain of species and then the route of transmission would further have to be broken down. Accumulation and Transmission are key to the threshold from sub-clinical to clinical disease, and key to all this, is to stop the amplification and transmission of this agent, the spreading of, no matter what strain. In my opinion, to continue with this myth that the U.K. strain of BSE (one strain TSE in cows), and the nv/v CJD (one strain TSE humans) and that all the rest of human TSE are just one single strain i.e. sporadic CJD (when to date there are 6 different phenotypes of sCJD, and growing per Gambetti et al), and that no other animal TSE transmits to humans, to continue with this masquerade will only continue to spread, expose, and kill, who knows how many more in the years and decades to come. ONE was enough for me, My Mom, hvCJD i.e. Heidenhain Variant CJD, DOD 12/14/97 confirmed, which is nothing more than another mans name added to CJD, like CJD itself, Jakob and Creutzfeldt, or Gerstmann-Straussler-Scheinker syndrome, just another CJD or human TSE, named after another human.WE are only kidding ourselves with the current diagnostic criteria for human and animal TSE, especially differentiating between the nvCJD vs the sporadic CJD strains and then the GSS strains and also the FFI fatal familial insomnia strains or the ones that mimics one or the other of those TSE? Tissue infectivity and strain typing of the many variantsManuscriptof the human and animal TSEs are paramount in all variants of all TSE. There must be a proper classification that will differentiate between all these human TSE in order to do this. With the CDI and other more sensitive testing coming about, I only hope that my proposal will some day be taken seriously. ...Terry S. Singeltary Sr. P.O. Box Bacliff, Texas USA 77518 flounder9@verizon.net
Terry S. Singeltary Sr.
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