Tuesday, March 15, 2016

Docket No. FDA-2016-N-0321 Risk Assessment of Foodborne Illness Associated with Pathogens from Produce Grown in Fields Amended with Untreated Biological Soil Amendments of Animal Origin; Request for Comments, Scientific Data, and Information Singeltary Submission

Docket No. FDA-2016-N-0321 Risk Assessment of Foodborne Illness Associated with Pathogens from Produce Grown in Fields Amended with Untreated Biological Soil Amendments of Animal Origin; Request for Comments, Scientific Data, and Information
 
Greetings FDA et al, I kindly would like to make comment submission to ;
 
Docket No. FDA-2016-N-0321 Risk Assessment of Foodborne Illness Associated with Pathogens from Produce Grown in Fields Amended with Untreated Biological Soil Amendments of Animal Origin; Request for Comments, Scientific Data, and Information
 
A Notice by the Food and Drug Administration on 03/04/2016
 
This document has a comment period that ends in 54 days (05/03/2016)
 
Action Notice; Request For Comments And For Scientific Data And Information.
 
Summary The Food and Drug Administration (FDA or we) is requesting scientific data, information, and comments that would assist the Agency in its plan to develop a risk assessment for produce grown in fields or other growing areas amended with untreated biological soil amendments of animal origin (including raw manure). The risk assessment will evaluate and, if feasible, quantify the risk of human illness associated with consumption of produce grown in fields or other growing areas amended with untreated biological soil amendments of animal origin that are potentially contaminated with enteric pathogens, such as Escherichia coli O157:H7 or Salmonella. The risk assessment also will evaluate the impact of certain interventions, such as use of a time interval between application of the soil amendment and crop harvest, on the predicted risk. The risk assessment is intended to inform policy decisions with regard to produce safety.
 
Table of Contents Back to Top DATES: ADDRESSES: Electronic Submissions Written/Paper Submissions FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: I. Background A. What are the food safety concerns related to untreated biological soil amendments of animal origin? B. How did FDA's rule on produce safety address BSAAO? II. FDA's Risk Assessment III. Issues for Consideration IV. Reference DATES: Back to Top Submit either electronic or written comments and scientific data and information by May 3, 2016.
 
ADDRESSES: Back to Top You may submit comments and scientific data and information as follows:
 
SNIP...
 
SUPPLEMENTARY INFORMATION: Back to Top
 
I. Background Back to Top A. What are the food safety concerns related to untreated biological soil amendments of animal origin? Biological soil amendments of animal origin (BSAAO) can be a source of contamination of produce with pathogens that can cause human illness. Human pathogens in BSAAO, once introduced to the growing environment, may be inactivated at a rate that is dependent upon a number of environmental, regional, and other agricultural and ecological factors. The rate of pathogen population decline over time is also influenced by the types of BSAAO and application methods. Furthermore, the types of produce and whether or not BSAAO may come into contact with a harvestable portion of the crop influences the likelihood of pathogen transfer from the amended soil to produce (Ref. 1).
 
Some produce farms use untreated BSAAO for various reasons, including that they are inexpensive, readily available, and rich nutrient sources for growing crops. Whether it is feasible for a farm to use untreated BSAAO as a principal nutrient source depends on numerous factors, including whether there is a required time interval between application and harvest and the length of such an interval (which may affect the nutrients retained or available from BSAAO), and crop nutrient demand (i.e., the nutrients needed to support crop growth). Typical examples of untreated BSAAO are raw cattle manure, poultry litter, swine slurry, and horse manure. FDA acknowledges that required application intervals for certain uses of untreated BSAAO could influence the number of crop cycles a farm is able to undertake each year and/or the choices farms make regarding which type of amendment to apply (e.g., raw manure, composted manure, or other nutrient sources).
 
B. How did FDA's rule on produce safety address BSAAO? In January 2013, based in part upon authority provided by the FDA Food Safety Modernization Act, we published a proposed Produce Safety Rule entitled “Standards for the Growing, Harvesting, Packing, and Holding of Produce for Human Consumption” (78 FR 3504, January 16, 2013). Among other provisions related to BSAAO, the proposed rule included at § 112.56(a)(1)(i) (21 CFR 112.56(a)(1)(i)) a 9-month minimum application interval for untreated BSAAO applied in a manner that does not contact covered produce during application and minimizes the potential for contact with covered produce after application (78 FR 3504 at 3637). In response to public comments, we withdrew this proposed 9-month minimum application interval in a supplemental proposed rulemaking that we published on September 29, 2014 (79 FR 58434 at 58457 through 58461). In the supplemental proposed rule, we acknowledged the limited body of currently available scientific evidence relating to the proposed 9-month interval and the need for additional research in this area, and described our planned risk assessment and research agenda (79 FR 58434 at 58460 through 58461). Accordingly, we deferred our decision on an appropriate minimum application interval.
 
On November 27, 2015, we published a final Produce Safety Rule entitled “Standards for the Growing, Harvesting, Packing, and Holding of Produce for Human Consumption,” (80 FR 74354). The final rule is now codified at 21 CFR part 112. In the preamble to the final rule, we restated our decision with respect to the appropriate minimum BSAAO application interval (80 FR 74354 at 74463). We reserved one of the provisions in the final rule's Subpart F (Biological Soil Amendments of Animal Origin and Human Waste) because we continue to believe that a quantitative application interval standard is necessary and anticipate locating such a future standard in that provision. As finalized, the Produce Safety Rule establishes that there is no minimum application interval required when untreated BSAAO are applied in a manner that does not contact covered produce during or after application (§ 112.56(a)(1)(ii)), and the minimum application interval is [reserved] when applied in a manner that does not contact produce during application and minimizes the potential for contact with produce after application (§ 112.56(a)(1)(i)).
 
II. FDA's Risk Assessment Back to Top FDA, in consultation with the U.S. Department of Agriculture, is conducting a risk assessment to evaluate the risk of human illness associated with the consumption of produce grown in growing areas amended with untreated BSAAO that are potentially contaminated with enteric pathogens such as E. coli O157:H7 or Salmonella. The risk assessment will evaluate the impact of different agricultural and ecological conditions and certain interventions, such as use of a time interval or intervals between application of untreated BSAAO and crop harvest, on the predicted risk. The risk assessment will take into account available data and information on relevant steps in the produce food safety continuum including: The initial prevalence and levels of pathogens in untreated BSAAO; the methods used to apply untreated BSAAO to soils; pathogen survival (and growth) in untreated BSAAO and soils amended with untreated BSAAO; pathogen transfer to produce grown in amended soils; pathogen survival and growth on produce; and pathogen survival, growth, and cross-contamination during storage and other steps in the supply chain (e.g., washing). The risk assessment will include characterization of the variability and uncertainty of pathogen survival and growth under different agricultural and ecological conditions (e.g., soil types, application methods, or geographic locations/climatic factors) and time intervals between application of untreated BSAAO and crop harvest. The risk assessment is intended to inform policy decisions with regard to produce safety.
 
III. Issues for Consideration Back to Top FDA is requesting comments and scientific data and other information relevant to this risk assessment. We are particularly interested in scientific data and information concerning, but not limited to, the following factors that may affect the risk of human illness associated with the consumption of produce grown in fields or other growing areas amended with untreated BSAAO (including raw manure):
 
1. Data on the prevalence and levels of pathogens.
 
a. The frequency of detecting the presence of pathogens in untreated BSAAO and soil amended with BSAAO, such as Salmonella in poultry litter, and E. coli O157:H7 and other pathogenic Shiga-toxin producing E. coli in cattle manure. Samples may be obtained at different stages of untreated BSAAO storage prior to application, or after application. If available, for each data point, we also invite information regarding the following:
 
The type of untreated BSAAO (e.g., animal origin and content);
 
how the untreated BSAAO, including raw manure, was sampled and handled prior to analysis;
 
the size of the analytical unit (i.e., detection limit) and test method;
 
the number of positives, the total number of samples, and the time period in which the testing was conducted; and
 
sampling protocol (e.g., simple random, stratified random, targeted).
 
b. The pathogen concentration, i.e., the number of pathogen cells per amount (unit volume or weight), in contaminated untreated BSAAO or soil amended with untreated BSAAO, especially cattle manure and poultry litter. If available, for each data point, we ask that the data be provided in unaggregated form and that Most Probable Number (MPN) patterns as well as raw data (e.g., number of positive and negative tubes per serial dilution) be provided.
 
2. Data and information on survival of pathogens (e.g., Salmonella, E. coli O157:H7), and pathogen transfer to produce.
 
a. Kinetic data that describe the survival (or inactivation) or growth of pathogens in untreated BSAAO, especially cattle manure and poultry litter;
 
b. Kinetic data that describe the survival (or inactivation) or growth of pathogens in soil amended with untreated BSAAO, especially cattle manure and poultry litter, as influenced by soil type, untreated BSAAO type, application method, geographic locations/climatic factors (e.g., temperature, days of sunlight, intensity of solar irradiation, moisture, rainfall) and other factors;
 
c. The mechanisms for pathogen transfer from soils to specific types or categories of produce, such as leafy greens, or to produce generally, and associated transfer coefficients, including irrigation and rain water splash, direct contact between produce and soil, machinery or people or animals contaminated by soil and directly contacting produce during growth and harvest of produce;
 
d. Pathogen transfer rates (i.e., transfer coefficients) from amended soils to specific types or categories of produce, such as leafy greens, or to produce generally, as influenced by soil type, untreated BSAAO type, application method, climate factors, commodity type or any other pertinent factors not listed here;
 
e. The survival of pathogens on produce in the field or other growing area before harvest; and
 
f. The variability in the survival of different Salmonella serotypes, different subtypes of E. coli O157:H7, or other pathogens of public health significance in amended soils under field, greenhouse, or laboratory conditions.
 
3. On-farm practices with regard to the use of untreated BSAAO, including, but not limited to, the following aspects.
 
a. The extent to which untreated BSAAO are used in different regions in the United States, as well outside the United States in regions that export produce to the United States;
 
b. The types of untreated BSAAO and the soil type, and associated physical and chemical parameters (including but not exclusive to nutrient content, moisture and pH); and the crops typically grown in each BSAAO-amended soil type;
 
c. Characterization of the proportion of produce farms that have one or more soil types per geographical location;
 
d. The amount of untreated BSAAO applied per unit surface (e.g., per acre) or the ratio of untreated BSAAO/soil, including typical ratio and variability by commodity type, including, for example, row crops such as leafy greens;
 
e. The time of year, number of applications, and amount of untreated BSAAO that are applied;
 
f. The method of application (e.g., surface, incorporated), and whether or not the amended soil is covered (e.g., with plastic mulch);
 
g. Produce commodity type and cropping cycles;
 
h. Climate conditions and irrigation practices after soil is amended, before and after planting; and
 
i. The crop density (e.g., the number of rows per bed, and the distance between adjacent rows in a bed), distance between two crop beds (furrow width), and the influence of such factors on pathogen transfer.
 
4. Harvesting, handling, and storage conditions that may affect pathogen detection and levels, survival, growth, or inactivation between harvest and retail sale along the farm-to-fork continuum.
 
a. The harvesting practices and the average conditions as well as the range of climactic conditions prior to harvesting (e.g., time and temperature, rain events) under which produce is handled in the field and in packing operations;
 
b. The survival, growth, or inactivation of pathogens on produce (including, for example, specific commodities or categories such as leafy greens, or produce generally) during transportation and storage;
 
c. Typical storage conditions (e.g., time, temperature) for produce (including, for example, specific commodities or categories, such as leafy greens, or produce generally), from harvest until consumer purchase and whether and how those storage conditions affect pathogen levels; and
 
d. The types and concentration of antimicrobial chemicals or other treatments, if any, applied to the water used for wash or transport of produce during farm or other distribution operations prior to retail, and the efficacy of these treatments in reducing pathogen levels, as well as the likelihood of cross-contamination during wash or transport.
 
5. Storage conditions such as times and temperatures that may affect pathogen growth and/or survival during transportation and storage of produce in the consumer's home, and consumer handling practices with respect to produce after purchase, including data and information on consumer washing practices.
 
We are also interested in other comments concerning, but not limited to, the types of untreated BSAAO, produce commodities, relevant agricultural and ecological conditions, and appropriate mitigation strategies that the Agency should consider in the risk assessment.
 
IV. Reference Back to Top The following reference is on display in the Division of Dockets Management (see ADDRESSES) and is available for viewing by interested persons between 9 a.m. and 4 p.m., Monday through Friday; they are also available electronically at http://www.regulations.gov. FDA has verified the Web site address, as of the date this document publishes in the Federal Register, but Web sites are subject to change over time.
 
1. Food and Drug Administration, 2015. “Final Qualitative Assessment of Risk to Public Health from On-Farm Contamination of Produce.” Available at: http://www.fda.gov/downloads/Food/FoodScienceResearch/RiskSafetyAssessment/UCM470780.pdf. Accessed January 20, 2016. Show citation box
 
Dated: February 29, 2016.
 
Leslie Kux,
 
Associate Commissioner for Policy.
 
 
 
COMMENT
 
 
 
Greetings FDA et al,
 
I kindly would like to make comment submission to Docket No. FDA-2016-N-0321 Risk Assessment of Foodborne Illness Associated with Pathogens from Produce Grown in Fields Amended with Untreated Biological Soil Amendments of Animal Origin; Request for Comments, Scientific Data, and Information
 
MY comment as follows,
 
There has been proven documented risk for Untreated Biological Soil Amendments of Animal Origin and risk of transmitting Transmissible Spongiform Encephalopathy TSE Prion disease aka mad cow type disease such as the typical and atypical Bovine Spongiform Encephalopathy strains, typical and atypical Scrapie strains, typical and atypical Chronic Wasting Disease CWD strains, and even the Transmissible Mink Encephalopathy TME Prion disease.
 
Science has shown that infected deer harbor and shed high levels of infectious prions in saliva, blood, urine, and feces thereby leading to transmission by direct contact and environmental contamination.
 
Ingestion of prion contaminated leaves and roots produced disease with a 100% attack rate and an incubation period not substantially longer than feeding animals directly with scrapie brain homogenate.
 
Plants can uptake prions from contaminated soil and transport them to different parts of the plant tissue (stem and leaves) [please see data from Soto et al Prion2015 Conference below in Science reference data].
 
Also, Detection of protease-resistant cervid prion protein in water from a CWD-endemic area is very concerning.
 
Science has shown that soil plays a role in the spreading and transmission of the CWD and Scrapie TSE prion agent.
 
For these reason and more (see reference materials) I urge the FDA to stop this practice of Untreated Biological Soil Amendments of Animal Origin, including blood, for use on our produce grown in fields, for the following reasons ;
 
PL1
 
Using in vitro prion replication for high sensitive detection of prions and prionlike proteins and for understanding mechanisms of transmission.
 
Claudio Soto
 
Mitchell Center for Alzheimer's diseases and related Brain disorders, Department of Neurology, University of Texas Medical School at Houston.
 
SNIP...
 
***Recently, we have been using PMCA to study the role of environmental prion contamination on the horizontal spreading of TSEs. These experiments have focused on the study of the interaction of prions with plants and environmentally relevant surfaces. Our results show that plants (both leaves and roots) bind tightly to prions present in brain extracts and excreta (urine and feces) and retain even small quantities of PrPSc for long periods of time. Strikingly, ingestion of prion contaminated leaves and roots produced disease with a 100% attack rate and an incubation period not substantially longer than feeding animals directly with scrapie brain homogenate. Furthermore, plants can uptake prions from contaminated soil and transport them to different parts of the plant tissue (stem and leaves). Similarly, prions bind tightly to a variety of environmentally relevant surfaces, including stones, wood, metals, plastic, glass, cement, etc. Prion contaminated surfaces efficiently transmit prion disease when these materials were directly injected into the brain of animals and strikingly when the contaminated surfaces were just placed in the animal cage. These findings demonstrate that environmental materials can efficiently bind infectious prions and act as carriers of infectivity, suggesting that they may play an important role in the horizontal transmission of the disease.
 
========================
 
Since its invention 13 years ago, PMCA has helped to answer fundamental questions of prion propagation and has broad applications in research areas including the food industry, blood bank safety and human and veterinary disease diagnosis.
 
 
PMCA Detection of CWD Infection in Cervid and Non-Cervid Species
 
Hoover, Edward Arthur Colorado State University-Fort Collins, Fort Collins, CO, United States
 
ABSTRACT Chronic wasting disease (CWD) of deer and elk is an emerging highly transmissible prion disease now recognized in 18 States, 2 Canadian provinces, and Korea.
 
***We have shown that Infected deer harbor and shed high levels of infectious prions in saliva, blood, urine, and feces, and in the tissues generating those body fluids and excreta, thereby leading to facile transmission by direct contact and environmental contamination.
 
***We have also shown that CWD can infect some non-cervid species, thus the potential risk CWD represents to domestic animal species and to humans remains unknown.
 
SNIP...
 
Public Health Relevance Chronic wasting disease (CWD) of deer and elk is an emergent highly transmissible prion disease now recognized throughout the USA as well as in Canada and Korea. We have shown that infected deer harbor and shed high levels of infectious prions in saliva, blood, urine, and feces thereby leading to transmission by direct contact and environmental contamination. In that our studies have also shown that CWD can infect some non-cervid species, the potential risk CWD may represents to domestic animal species and humans remains unknown. The increasing parallels in the development of major human neurodegenerative conditions, such as Alzheimer's and Parkinson's diseases, and prion diseases add relevance to CWD as a model of a transmissible protein misfolding disease. Understanding how infectious misfolded proteins (prions) are generated and transmitted will aid in interrupting, treating, and managing the risks associated with these agents and the diseases they cause.
 
 
Prion Amplification and Hierarchical Bayesian Modeling Refine Detection of Prion Infection
 
A. Christy Wyckoff1, 2 n1 , Nathan Galloway3 n1 , Crystal Meyerett-Reid1 , Jenny Powers4 , Terry Spraker1 , Ryan J. Monello4 , Bruce Pulford1 , Margaret Wild4 , Michael Antolin3 , Kurt VerCauteren2 […] & Mark Zabel
 
Infected animals shed prions into the environment through saliva, feces, urine and even antler velvet15,20,21,22,23,24. Studies have successfully transmitted PrPCWD through a single dose of urine or feces from animals displaying signs of CWD, indicating that at the time of clinical disease sufficient prions are shed to result in an infectious dose24,25. However, at what stage(s) of disease animals shed prions into the environment remains unclear. If shedding occurs early in disease, a sub-clinical animal may not only shed prions into the environment, increasing the infectious reservoir, but may also transmit CWD horizontally to their associates.
 
 
Short Communication
 
Early detection of chronic wasting disease prions in urine of pre-symptomatic deer by real-time quaking-induced conversion assay
 
Volume 7, Issue 3 May/June 2013
 
Pages 253 – 258
 
 
Keywords: RT-QuIC, chronic wasting disease, diagnosis, feces, prion, surveillance, urine
 
Authors: Theodore R. John, Hermann M. Schätzl and Sabine Gilch
 
Theodore R. John Department of Veterinary Sciences; University of Wyoming; Laramie, WY USA
 
Hermann M. Schätzl Department of Veterinary Sciences; University of Wyoming; Laramie, WY USA; Department of Molecular Biology; University of Wyoming; Laramie, WY USA; Faculty of Veterinary Medicine; Department of Comparative Biology and Experimental Medicine; University of Calgary; Calgary, AB Canada
 
Sabine Gilch Corresponding author: sgilch@ucalgary.ca Department of Veterinary Sciences; University of Wyoming; Laramie, WY USA; Faculty of Veterinary Medicine; Department of Ecosystem and Public Health; University of Calgary; Calgary, AB Canada
 
Abstract:
 
Chronic wasting disease (CWD) is a prion disease of captive and free-ranging deer (Odocoileus spp), elk (Cervus elaphus nelsonii) and moose (Alces alces shirasi). Unlike in most other prion diseases, in CWD prions are shed in urine and feces, which most likely contributes to the horizontal transmission within and between cervid species. To date, CWD ante-mortem diagnosis is only possible by immunohistochemical detection of protease resistant prion protein (PrPSc) in tonsil or recto-anal mucosa-associated lymphoid tissue (RAMALT) biopsies, which requires anesthesia of animals. We report on detection of CWD prions in urine collected from pre-symptomatic deer and in fecal extracts by using real time quaking-induced conversion (RT-QuIC). This assay can be useful for non-invasive pre-symptomatic diagnosis and surveillance of CWD.
 
Received: February 7, 2013; Accepted: March 24, 2013; Published Online: April 10, 2013
 
snip...
 
Introduction
 
Chronic wasting disease (CWD) is to date the most contagious prion disease and affects captive and free-ranging elk, deer and moose in North America.1,2 The disease is caused by the accumulation of an abnormally folded isoform of the cellular prion protein PrPC, denominated PrPSc.3,4 CWD is the cervid equivalent of bovine spongiform encephalopathy (BSE), scrapie in sheep and goat5 or Creutzfeldt-Jakob disease (CJD) in humans.6 Although transmission studies of CWD prions to humanized transgenic mice or non-human primates suggest a strong species barrier,7-9 recent in vitro studies have demonstrated that human PrP can be converted by CWD prions into PrPSc upon adaptation.10 Therefore, a potential for zoonotic transmission, as exemplified by BSE,11 cannot be completely excluded.
 
A huge body of evidence suggests that CWD can be efficiently transmitted horizontally within and between cervid species,12 which may be the reason for geographical spread and increase in case numbers. Horizontal transmission is explained by the rather unusual peripheral distribution of prions in CWD affected animals and the high susceptibility to the disease by oral infection.13,14 Unlike in most other prion diseases, CWD prions can be found in a wide variety of tissues, such as skeletal and cardiac muscle15,16 or kidney,17 in addition to the lymphoreticular system and blood.18 Furthermore, they are shed in significant amounts in saliva,18,19 urine19 or feces,20 which enables oral infection of animals by foraging on contaminated pastures.
 
In addition, it has been demonstrated that prions can persist in soil21 and that water in endemic areas can contain CWDassociated PrPSc.22
 
snip...
 
We demonstrate that CWD prions are detectable in urine of orally infected deer prior to the onset of clinical symptoms. Furthermore, we show that fecal extracts can be used as a seed in RT-QuIC assays. Thereby, we were able to detect CWD prions in fecal extracts collected at later stages of the disease. This study provides the first evidence that RT-QuIC can be successfully used for the preclinical diagnosis of CWD in specimens that are available by non-invasive methods.
 
snip...
 
In summary, we demonstrate that CWD prions can be detected by RT-QuIC in urine of orally infected white-tailed deer and mule deer at a pre-symptomatic stage of the disease.
 
snip...
 
 
Oral Transmissibility of Prion Disease Is Enhanced by Binding to Soil Particles
 
Author Summary
 
Transmissible spongiform encephalopathies (TSEs) are a group of incurable neurological diseases likely caused by a misfolded form of the prion protein. TSEs include scrapie in sheep, bovine spongiform encephalopathy (‘‘mad cow’’ disease) in cattle, chronic wasting disease in deer and elk, and Creutzfeldt-Jakob disease in humans. Scrapie and chronic wasting disease are unique among TSEs because they can be transmitted between animals, and the disease agents appear to persist in environments previously inhabited by infected animals. Soil has been hypothesized to act as a reservoir of infectivity and to bind the infectious agent. In the current study, we orally dosed experimental animals with a common clay mineral, montmorillonite, or whole soils laden with infectious prions, and compared the transmissibility to unbound agent. We found that prions bound to montmorillonite and whole soils remained orally infectious, and, in most cases, increased the oral transmission of disease compared to the unbound agent. The results presented in this study suggest that soil may contribute to environmental spread of TSEs by increasing the transmissibility of small amounts of infectious agent in the environment.
 
 
see ;
 
Potential role of soil properties in the spread of CWD in western Canada
 
Alsu Kuznetsova1*, Debbie McKenzie2, Pamela Banser2, Tariq Siddique1, and Judd M. Aiken2 1Department of Renewable Resources; University of Alberta; Edmonton, AB Canada; 2Centre for Prions and Protein Folding Diseases; University of Alberta; Edmonton, AB Canada
 
Keywords: CWD expanding, prion, soil texture, soil organic matter, soil pH
 
Chronic wasting disease (CWD) is a horizontally transmissible prion disease of free ranging deer, elk and moose. Recent experimental transmission studies indicate caribou are also susceptible to the disease. CWD is present in southeast Alberta and southern Saskatchewan. This CWDendemic region is expanding, threatening Manitoba and areas of northern Alberta and Saskatchewan, home to caribou. Soil can serve as a stable reservoir for infectious prion proteins; prions bound to soil particles remain infectious in the soils for many years. Soils of western Canada are very diverse and the ability of CWD prions to bind different soils and the impact of this interaction on infectivity is not known. In general, clay-rich soils may bind prions avidly and enhance their infectivity comparable to pure clay mineral montmorillonite. Organic components of soils are also diverse and not well characterized, yet can impact prion-soil interaction. Other important contributing factors include soil pH, composition of soil solution and amount of metals (metal oxides). In this review, properties of soils of the CWD-endemic region in western Canada with its surrounding terrestrial environment are described and used to predict bioavailability and, thus, potential spread of CWD. The major soils in the CWD-endemic region of Alberta and Saskatchewan are Chernozems, present in 60% of the total area; they are generally similar in texture, clay mineralogy and soil organic matter content, and can be characterized as clay loamy, montmorillonite (smectite) soils with 6 - 10% organic carbon. The greatest risk of CWD spread in western Canada relates to clay loamy, montmorillonite soils with humus horizon. Such soils are predominant in the southern region of Alberta, Saskatchewan and Manitoba, but are less common in northern regions of the provinces where quartz-illite sandy soils with low amount of humus prevail.
 
Introduction ...snip...end
 
 
 Research Article
 
Estimating Prion Adsorption Capacity of Soil by BioAssay of Subtracted Infectivity from Complex Solutions (BASICS)
 
Estimating Prion Adsorption Capacity of Soil by BioAssay of Subtracted Infectivity from Complex Solutions (BASICS) A. Christy Wyckoff, Krista L. Lockwood, Crystal Meyerett-Reid, Brady A. Michel, Heather Bender, Kurt C. VerCauteren, Mark D. Zabel PLOS x Published: March 4, 2013 DOI: 10.1371/journal.pone.0058630
 
Abstract Prions, the infectious agent of scrapie, chronic wasting disease and other transmissible spongiform encephalopathies, are misfolded proteins that are highly stable and resistant to degradation. Prions are known to associate with clay and other soil components, enhancing their persistence and surprisingly, transmissibility. Currently, few detection and quantification methods exist for prions in soil, hindering an understanding of prion persistence and infectivity in the environment. Variability in apparent infectious titers of prions when bound to soil has complicated attempts to quantify the binding capacity of soil for prion infectivity. Here, we quantify the prion adsorption capacity of whole, sandy loam soil (SLS) typically found in CWD endemic areas in Colorado; and purified montmorillonite clay (Mte), previously shown to bind prions, by BioAssay of Subtracted Infectivity in Complex Solutions (BASICS). We incubated prion positive 10% brain homogenate from terminally sick mice infected with the Rocky Mountain Lab strain of mouse-adapted prions (RML) with 10% SLS or Mte. After 24 hours samples were centrifuged five minutes at 200×g and soil-free supernatant was intracerebrally inoculated into prion susceptible indicator mice. We used the number of days post inoculation to clinical disease to calculate the infectious titer remaining in the supernatant, which we subtracted from the starting titer to determine the infectious prion binding capacity of SLS and Mte. BASICS indicated SLS bound and removed ≥ 95% of infectivity. Mte bound and removed lethal doses (99.98%) of prions from inocula, effectively preventing disease in the mice. Our data reveal significant prion-binding capacity of soil and the utility of BASICS to estimate prion loads and investigate persistence and decomposition in the environment. Additionally, since Mte successfully rescued the mice from prion disease, Mte might be used for remediation and decontamination protocols.
 
 
 
 
 Behavior of Prions in the Environment: Implications for Prion Biology
 
Shannon L. Bartelt-Hunt1*, Jason C. Bartz2*
 
1 Department of Civil Engineering, University of Nebraska-Lincoln, Peter Kiewit Institute, Omaha, Nebraska, United States of America, 2 Department of Medical Microbiology and Immunology, Creighton University, Omaha, Nebraska, United States of America
 
Emergence of Prion Diseases
 
Prion diseases are infectious, potentially zoonotic neurodegenerative diseases of animals including humans that are inevitably fatal and are caused by prions. Prions are comprised of a misfolded isoform of the normal prion protein, PrPC, into the infectious conformation, PrPSc [1]. Of the known prion diseases, chronic wasting disease (CWD) of deer, elk, and moose is emerging. CWD was first identified in captive deer in the front range of Colorado and Wyoming in the 1960s and has since been identified in captive and free-ranging cervids in 20 states, two Canadian provinces, and South Korea (for latest disease distribution please see http://www. nwhc.usgs.gov/disease_information/chronic_wasting_disease/index. jsp).While there is evidence of the spread ofCWDalong known cervid home ranges, the mechanism underlying the emergence of CWD in geographically isolated areas is not understood. The prevalence of CWD within an affected population is generally lower than 5%; however, there are reports of incidence rates that approach 50%. Transmission of CWD can occur horizontally or through CWDcontaminated environments, but the relative contribution of each mode in the overall transmission of CWD is unknown [2]. Since effective control measures are not available, it is likely that CWD will continue to spread in North America. The effect of this on the wellbeing of the cervid population and the risk of transmission to other species is not known.
 
 
Prion Amplification and Hierarchical Bayesian Modeling Refine Detection of Prion Infection A. Christy Wyckoff1, 2 n1 , Nathan Galloway3 n1 , Crystal Meyerett-Reid1 , Jenny Powers4 , Terry Spraker1 , Ryan J. Monello4 , Bruce Pulford1 , Margaret Wild4 , Michael Antolin3 , Kurt VerCauteren2 […] & Mark Zabel1 - Show fewer authors Scientific Reports 5, Article number: 8358 (2015) doi:10.1038/srep08358 Download Citation
 
Molecular ecology Proteins Statistics Received: 27 June 2014 Accepted: 19 January 2015 Published online: 10 February 2015 Abstract Prions are unique infectious agents that replicate without a genome and cause neurodegenerative diseases that include chronic wasting disease (CWD) of cervids. Immunohistochemistry (IHC) is currently considered the gold standard for diagnosis of a prion infection but may be insensitive to early or sub-clinical CWD that are important to understanding CWD transmission and ecology. We assessed the potential of serial protein misfolding cyclic amplification (sPMCA) to improve detection of CWD prior to the onset of clinical signs. We analyzed tissue samples from free-ranging Rocky Mountain elk (Cervus elaphus nelsoni) and used hierarchical Bayesian analysis to estimate the specificity and sensitivity of IHC and sPMCA conditional on simultaneously estimated disease states. Sensitivity estimates were higher for sPMCA (99.51%, credible interval (CI) 97.15–100%) than IHC of obex (brain stem, 76.56%, CI 57.00–91.46%) or retropharyngeal lymph node (90.06%, CI 74.13–98.70%) tissues, or both (98.99%, CI 90.01–100%). Our hierarchical Bayesian model predicts the prevalence of prion infection in this elk population to be 18.90% (CI 15.50–32.72%), compared to previous estimates of 12.90%. Our data reveal a previously unidentified sub-clinical prion-positive portion of the elk population that could represent silent carriers capable of significantly impacting CWD ecology.
 
Introduction
 
 
 Grass Plants Bind, Retain, Uptake, and Transport Infectious Prions
 
Authors
 
Sandra Pritzkow, Rodrigo Morales, ..., Edward Hoover, Claudio Soto
 
Correspondence
 
claudio.soto@uth.tmc.edu
 
In Brief
 
Prions are the proteinaceous infectious agents responsible for prion diseases. Pritzkow et al. report that prions from brain and excreta can bind grass plants and remain attached to living plants for a long time and that contaminated plants can infect animals. In addition, grass plants can uptake and transport prions from infected soil.
 
Pritzkow et al., 2015, Cell Reports 11, 1168–1175 May 26, 2015 ª2015 The Authors http://dx.doi.org/10.1016/j.celrep.2015.04.036
 
SUMMARY
 
Prions are the protein-based infectious agents responsible for prion diseases. Environmental prion contamination has been implicated in disease transmission. Here, we analyzed the binding and retention of infectious prion protein (PrPSc) to plants. Small quantities of PrPSc contained in diluted brain homogenate or in excretory materials (urine and feces) can bind to wheat grass roots and leaves. Wild-type hamsters were efficiently infected by ingestion of prion-contaminated plants. The prion-plant interaction occurs with prions from diverse origins, including chronic wasting disease. Furthermore, leaves contaminated by spraying with a prion-containing preparation retained PrPSc for several weeks in the living plant. Finally, plants can uptake prions from contaminated soil and transport them to aerial parts of the plant (stem and leaves). These findings demonstrate that plants can efficiently bind infectious prions and act as carriers of infectivity, suggesting a possible role of environmental prion contamination in the horizontal transmission of the disease. INTRODUCTION
 
 
*** Infectious agent of sheep scrapie may persist in the environment for at least 16 years ***
 
Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3
 
 
*** Spraker suggested an interesting explanation for the occurrence of CWD. The deer pens at the Foot Hills Campus were built some 30-40 years ago by a Dr. Bob Davis. At or abut that time, allegedly, some scrapie work was conducted at this site. When deer were introduced to the pens they occupied ground that had previously been occupied by sheep.
 
 
COMERCIAL IN CONFIDENCE
 
SPREADING OF UNPROCESSED BLOOD ON LAND
 
 
*** Infectious agent of sheep scrapie may persist in the environment for at least 16 years ***
 
Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3
 
 
The BSE Inquiry / Statement No 19B (supplementary) Dr Alan Colchester Issued 06/08/1999 (not scheduled to give oral evidence) SECOND STATEMENT TO THE BSE INQUIRY Dr A Colchester BA BM BCh PhD FRCP Reader in Neurosciences & Computing, University of Kent at Canterbury; Consultant Neurologist, Guy’s Hospital London and William Harvey Hospital Ashford April 1999
 
snip...
 
88. Natural decay: Infectivity persists for a long time in the environment. A study by Palsson in 1979 showed how scrapie was contracted by healthy sheep, after they had grazed on land which had previously been grazed by scrapie-infected sheep, even though the land had lain fallow for three years before the healthy sheep were introduced. Brown also quoted an early experiment of his own (1991), where he had buried scrapie-infected hamster brain and found that he could still detect substantial infectivity three years later near where the material had been placed. 89. Potential environmental routes of infection: Brown discusses the various possible scenarios, including surface or subsurface deposits of TSE-contaminated material, which would lead to a build-up of long-lasting infectivity. Birds feeding on animal remains (such as gulls visiting landfill sites) could disperse infectivity. Other animals could become vectors if they later grazed on contaminated land. "A further question concerns the risk of contamination of the surrounding water table or even surface water channels, by effluents and discarded solid wastes from treatment plants. A reasonable conclusion is that there is a potential for human infection to result from environmental contamination by BSE-infected tissue residues. The potential cannot be quantified because of the huge numbers of uncertainties and assumptions that attend each stage of the disposal process". These comments, from a long established authority on TSEs, closely echo my own statements which were based on a recent examination of all the evidence. 90. Susceptibility: It is likely that transmissibility of the disease to humans in vivo is probably low, because sheep that die from scrapie and cattle that die from BSE are probably a small fraction of the exposed population. However, no definitive data are available.
 
91. Recommendations for disposal procedures: Brown recommends that material which is actually or potentially contaminated by BSE should be: 1) exposed to caustic soda; 2) thoroughly incinerated under carefully inspected conditions; and 3) that any residue should be buried in landfill, to a depth which would minimise any subsequent animal or human exposure, in areas that would not intersect with any potable water-table source.
 
92. This review and recommendations from Brown have particular importance. Brown is one of the world's foremost authorities on TSEs and is a senior researcher in the US National Institutes of Health (NIH). It is notable that such a respected authority is forthright in acknowledging the existence of potential risks, and in identifying the appropriate measures necessary to safeguard public health. Paper by SM Cousens, L Linsell, PG Smith, Dr M Chandrakumar, JW Wilesmith, RSG Knight, M Zeidler, G Stewart, RG Will, "Geographical distribution of variant CJD in the UK (excluding Northern Ireland)". Lancet 353:18-21, 2 nd January 1999 93. The above paper {Appendix 41 (02/01/99)} (J/L/353/18) examined the possibility that patients with vCJD (variant CJD) might live closer to rendering factories than would be expected by chance. All 26 cases of vCJD in the UK with onset up to 31 st August 1998 were studied. The incubation period of vCJD is not known but by analogy with other human TSEs could lie within the range 5-25 years. If vCJD had arisen by exposure to rendering products, such exposure might plausibly have occurred 8-10 years before the onset of symptoms. The authors were able to obtain the addresses of all rendering plants in the UK which were in production in 1988. For each case of vCJD, the distance from the place of residence on 1st January 1998 to the nearest rendering plant was calculated
 
snip...
 
 
Survival of scrapie virus after 3 years
 
interment P Brown x P Brown Search for articles by this author Correspondence Correspondence to Dr Paul Brown. , PhD correspondence x P Brown Search for articles by this author Correspondence Correspondence to Dr Paul Brown. , D.C Gajdusek x D.C Gajdusek Search for articles by this author , MD Laboratory of CNS Studies, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, U.S.A.
 
 
PAUL BROWN SCRAPIE SOIL TEST
 
 
Paul Brown, known and respected TSE scientist, former TSE expert for the CDC said he had ''absolutely no confidence in USDA tests before one year ago'', and this was on March 15, 2006 ;
 
"The fact the Texas cow showed up fairly clearly implied the existence of other undetected cases," Dr. Paul Brown, former medical director of the National Institutes of Health's Laboratory for Central Nervous System Studies and an expert on mad cow-like diseases, told United Press International. "The question was, 'How many?' and we still can't answer that."
 
Brown, who is preparing a scientific paper based on the latest two mad cow cases to estimate the maximum number of infected cows that occurred in the United States, said he has "absolutely no confidence in USDA tests before one year ago" because of the agency's reluctance to retest the Texas cow that initially tested positive.
 
USDA officials finally retested the cow and confirmed it was infected seven months later, but only at the insistence of the agency's inspector general.
 
"Everything they did on the Texas cow makes everything USDA did before 2005 suspect," Brown said. ...snip...end
 
 
CDC - Bovine Spongiform Encephalopathy and Variant Creutzfeldt ... Dr. Paul Brown is Senior Research Scientist in the Laboratory of Central Nervous System ... Address for correspondence: Paul Brown, Building 36, Room 4A-05, ...
 
 
PAUL BROWN COMMENT TO ME ON THIS ISSUE
 
Tuesday, September 12, 2006 11:10 AM
 
"Actually, Terry, I have been critical of the USDA handling of the mad cow issue for some years, and with Linda Detwiler and others sent lengthy detailed critiques and recommendations to both the USDA and the Canadian Food Agency."
 
OR, what the Honorable Phyllis Fong of the OIG found ;
 
Finding 2 Inherent Challenges in Identifying and Testing High-Risk Cattle Still Remain
 
 
Wednesday, March 2, 2016
 
RANCHO He did not know that they were placing healthy cow heads next to suspect carcasses BSE TSE Prion
 
 
Wednesday, December 16, 2015
 
Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission
 
 
The sources of dust borne prions are unknown but it seems reasonable to assume that faecal, urine, skin, parturient material and saliva-derived prions may contribute to this mobile environmental reservoir of infectivity. This work highlights a possible transmission route for scrapie within the farm environment, and this is likely to be paralleled in CWD which shows strong similarities with scrapie in terms of prion dissemination and disease transmission. The data indicate that the presence of scrapie prions in dust is likely to make the control of these diseases a considerable challenge.
 
 
>>>Particle-associated PrPTSE molecules may migrate from locations of deposition via transport processes affecting soil particles, including entrainment in and movement with air and overland flow. <<<
 
Fate of Prions in Soil: A Review
 
Christen B. Smith, Clarissa J. Booth, and Joel A. Pedersen*
 
Several reports have shown that prions can persist in soil for several years. Significant interest remains in developing methods that could be applied to degrade PrPTSE in naturally contaminated soils. Preliminary research suggests that serine proteases and the microbial consortia in stimulated soils and compost may partially degrade PrPTSE. Transition metal oxides in soil (viz. manganese oxide) may also mediate prion inactivation. Overall, the effect of prion attachment to soil particles on its persistence in the environment is not well understood, and additional study is needed to determine its implications on the environmental transmission of scrapie and CWD.
 
 
P.161: Prion soil binding may explain efficient horizontal CWD transmission
 
Conclusion. Silty clay loam exhibits highly efficient prion binding, inferring a durable environmental reservoir, and an efficient mechanism for indirect horizontal CWD transmission.
 
 
Wednesday, December 16, 2015
 
Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission
 
Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission
 
Timm Konold1*, Stephen A. C. Hawkins2, Lisa C. Thurston3, Ben C. Maddison4, Kevin C. Gough5, Anthony Duarte1 and Hugh A. Simmons1
 
1 Animal Sciences Unit, Animal and Plant Health Agency Weybridge, Addlestone, UK, 2 Pathology Department, Animal and Plant Health Agency Weybridge, Addlestone, UK, 3 Surveillance and Laboratory Services, Animal and Plant Health Agency Penrith, Penrith, UK, 4 ADAS UK, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, UK, 5 School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, UK
 
Classical scrapie is an environmentally transmissible prion disease of sheep and goats. Prions can persist and remain potentially infectious in the environment for many years and thus pose a risk of infecting animals after re-stocking. In vitro studies using serial protein misfolding cyclic amplification (sPMCA) have suggested that objects on a scrapie affected sheep farm could contribute to disease transmission. This in vivo study aimed to determine the role of field furniture (water troughs, feeding troughs, fencing, and other objects that sheep may rub against) used by a scrapie-infected sheep flock as a vector for disease transmission to scrapie-free lambs with the prion protein genotype VRQ/VRQ, which is associated with high susceptibility to classical scrapie. When the field furniture was placed in clean accommodation, sheep became infected when exposed to either a water trough (four out of five) or to objects used for rubbing (four out of seven). This field furniture had been used by the scrapie-infected flock 8 weeks earlier and had previously been shown to harbor scrapie prions by sPMCA. Sheep also became infected (20 out of 23) through exposure to contaminated field furniture placed within pasture not used by scrapie-infected sheep for 40 months, even though swabs from this furniture tested negative by PMCA. This infection rate decreased (1 out of 12) on the same paddock after replacement with clean field furniture. Twelve grazing sheep exposed to field furniture not in contact with scrapie-infected sheep for 18 months remained scrapie free. The findings of this study highlight the role of field furniture used by scrapie-infected sheep to act as a reservoir for disease re-introduction although infectivity declines considerably if the field furniture has not been in contact with scrapie-infected sheep for several months. PMCA may not be as sensitive as VRQ/VRQ sheep to test for environmental contamination.
 
snip...
 
Discussion
 
Classical scrapie is an environmentally transmissible disease because it has been reported in naïve, supposedly previously unexposed sheep placed in pastures formerly occupied by scrapie-infected sheep (4, 19, 20). Although the vector for disease transmission is not known, soil is likely to be an important reservoir for prions (2) where – based on studies in rodents – prions can adhere to minerals as a biologically active form (21) and remain infectious for more than 2 years (22). Similarly, chronic wasting disease (CWD) has re-occurred in mule deer housed in paddocks used by infected deer 2 years earlier, which was assumed to be through foraging and soil consumption (23).
 
Our study suggested that the risk of acquiring scrapie infection was greater through exposure to contaminated wooden, plastic, and metal surfaces via water or food troughs, fencing, and hurdles than through grazing. Drinking from a water trough used by the scrapie flock was sufficient to cause infection in sheep in a clean building. Exposure to fences and other objects used for rubbing also led to infection, which supported the hypothesis that skin may be a vector for disease transmission (9). The risk of these objects to cause infection was further demonstrated when 87% of 23 sheep presented with PrPSc in lymphoid tissue after grazing on one of the paddocks, which contained metal hurdles, a metal lamb creep and a water trough in contact with the scrapie flock up to 8 weeks earlier, whereas no infection had been demonstrated previously in sheep grazing on this paddock, when equipped with new fencing and field furniture. When the contaminated furniture and fencing were removed, the infection rate dropped significantly to 8% of 12 sheep, with soil of the paddock as the most likely source of infection caused by shedding of prions from the scrapie-infected sheep in this paddock up to a week earlier.
 
This study also indicated that the level of contamination of field furniture sufficient to cause infection was dependent on two factors: stage of incubation period and time of last use by scrapie-infected sheep. Drinking from a water trough that had been used by scrapie sheep in the predominantly pre-clinical phase did not appear to cause infection, whereas infection was shown in sheep drinking from the water trough used by scrapie sheep in the later stage of the disease. It is possible that contamination occurred through shedding of prions in saliva, which may have contaminated the surface of the water trough and subsequently the water when it was refilled. Contamination appeared to be sufficient to cause infection only if the trough was in contact with sheep that included clinical cases. Indeed, there is an increased risk of bodily fluid infectivity with disease progression in scrapie (24) and CWD (25) based on PrPSc detection by sPMCA. Although ultraviolet light and heat under natural conditions do not inactivate prions (26), furniture in contact with the scrapie flock, which was assumed to be sufficiently contaminated to cause infection, did not act as vector for disease if not used for 18 months, which suggest that the weathering process alone was sufficient to inactivate prions.
 
PrPSc detection by sPMCA is increasingly used as a surrogate for infectivity measurements by bioassay in sheep or mice. In this reported study, however, the levels of PrPSc present in the environment were below the limit of detection of the sPMCA method, yet were still sufficient to cause infection of in-contact animals. In the present study, the outdoor objects were removed from the infected flock 8 weeks prior to sampling and were positive by sPMCA at very low levels (2 out of 37 reactions). As this sPMCA assay also yielded 2 positive reactions out of 139 in samples from the scrapie-free farm, the sPMCA assay could not detect PrPSc on any of the objects above the background of the assay. False positive reactions with sPMCA at a low frequency associated with de novo formation of infectious prions have been reported (27, 28). This is in contrast to our previous study where we demonstrated that outdoor objects that had been in contact with the scrapie-infected flock up to 20 days prior to sampling harbored PrPSc that was detectable by sPMCA analysis [4 out of 15 reactions (12)] and was significantly more positive by the assay compared to analogous samples from the scrapie-free farm. This discrepancy could be due to the use of a different sPMCA substrate between the studies that may alter the efficiency of amplification of the environmental PrPSc. In addition, the present study had a longer timeframe between the objects being in contact with the infected flock and sampling, which may affect the levels of extractable PrPSc. Alternatively, there may be potentially patchy contamination of this furniture with PrPSc, which may have been missed by swabbing. The failure of sPMCA to detect CWD-associated PrP in saliva from clinically affected deer despite confirmation of infectivity in saliva-inoculated transgenic mice was associated with as yet unidentified inhibitors in saliva (29), and it is possible that the sensitivity of sPMCA is affected by other substances in the tested material. In addition, sampling of amplifiable PrPSc and subsequent detection by sPMCA may be more difficult from furniture exposed to weather, which is supported by the observation that PrPSc was detected by sPMCA more frequently in indoor than outdoor furniture (12). A recent experimental study has demonstrated that repeated cycles of drying and wetting of prion-contaminated soil, equivalent to what is expected under natural weathering conditions, could reduce PMCA amplification efficiency and extend the incubation period in hamsters inoculated with soil samples (30). This seems to apply also to this study even though the reduction in infectivity was more dramatic in the sPMCA assays than in the sheep model. Sheep were not kept until clinical end-point, which would have enabled us to compare incubation periods, but the lack of infection in sheep exposed to furniture that had not been in contact with scrapie sheep for a longer time period supports the hypothesis that prion degradation and subsequent loss of infectivity occurs even under natural conditions.
 
In conclusion, the results in the current study indicate that removal of furniture that had been in contact with scrapie-infected animals should be recommended, particularly since cleaning and decontamination may not effectively remove scrapie infectivity (31), even though infectivity declines considerably if the pasture and the field furniture have not been in contact with scrapie-infected sheep for several months. As sPMCA failed to detect PrPSc in furniture that was subjected to weathering, even though exposure led to infection in sheep, this method may not always be reliable in predicting the risk of scrapie infection through environmental contamination. These results suggest that the VRQ/VRQ sheep model may be more sensitive than sPMCA for the detection of environmentally associated scrapie, and suggest that extremely low levels of scrapie contamination are able to cause infection in susceptible sheep genotypes.
 
Keywords: classical scrapie, prion, transmissible spongiform encephalopathy, sheep, field furniture, reservoir, serial protein misfolding cyclic amplification
 
 
Wednesday, December 16, 2015
 
*** Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission ***
 
 
Circulation of prions within dust on a scrapie affected farm
 
Kevin C Gough1, Claire A Baker2, Hugh A Simmons3, Steve A Hawkins3 and Ben C Maddison2*
 
Abstract
 
Prion diseases are fatal neurological disorders that affect humans and animals. Scrapie of sheep/goats and Chronic Wasting Disease (CWD) of deer/elk are contagious prion diseases where environmental reservoirs have a direct link to the transmission of disease. Using protein misfolding cyclic amplification we demonstrate that scrapie PrPSc can be detected within circulating dusts that are present on a farm that is naturally contaminated with sheep scrapie. The presence of infectious scrapie within airborne dusts may represent a possible route of infection and illustrates the difficulties that may be associated with the effective decontamination of such scrapie affected premises.
 
snip...
 
Discussion
 
We present biochemical data illustrating the airborne movement of scrapie containing material within a contaminated farm environment. We were able to detect scrapie PrPSc within extracts from dusts collected over a 70 day period, in the absence of any sheep activity. We were also able to detect scrapie PrPSc within dusts collected within pasture at 30 m but not at 60 m distance away from the scrapie contaminated buildings, suggesting that the chance of contamination of pasture by scrapie contaminated dusts decreases with distance from contaminated farm buildings. PrPSc amplification by sPMCA has been shown to correlate with infectivity and amplified products have been shown to be infectious [14,15]. These experiments illustrate the potential for low dose scrapie infectivity to be present within such samples. We estimate low ng levels of scrapie positive brain equivalent were deposited per m2 over 70 days, in a barn previously occupied by sheep affected with scrapie. This movement of dusts and the accumulation of low levels of scrapie infectivity within this environment may in part explain previous observations where despite stringent pen decontamination regimens healthy lambs still became scrapie infected after apparent exposure from their environment alone [16]. The presence of sPMCA seeding activity and by inference, infectious prions within dusts, and their potential for airborne dissemination is highly novel and may have implications for the spread of scrapie within infected premises. The low level circulation and accumulation of scrapie prion containing dust material within the farm environment will likely impede the efficient decontamination of such scrapie contaminated buildings unless all possible reservoirs of dust are removed. Scrapie containing dusts could possibly infect animals during feeding and drinking, and respiratory and conjunctival routes may also be involved. It has been demonstrated that scrapie can be efficiently transmitted via the nasal route in sheep [17], as is also the case for CWD in both murine models and in white tailed deer [18-20].
 
The sources of dust borne prions are unknown but it seems reasonable to assume that faecal, urine, skin, parturient material and saliva-derived prions may contribute to this mobile environmental reservoir of infectivity. This work highlights a possible transmission route for scrapie within the farm environment, and this is likely to be paralleled in CWD which shows strong similarities with scrapie in terms of prion dissemination and disease transmission. The data indicate that the presence of scrapie prions in dust is likely to make the control of these diseases a considerable challenge.
 
 
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...
 
 
Saturday, January 31, 2015
 
European red deer (Cervus elaphus elaphus) are susceptible to Bovine Spongiform Encephalopathy BSE by Oral Alimentary route
 
 
I strenuously once again urge the FDA and its industry constituents, to make it MANDATORY that all ruminant feed be banned to all ruminants, and this should include all cervids as soon as possible for the following reasons...
 
======
 
In the USA, under the Food and Drug Administrations 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.
 
======
 
31 Jan 2015 at 20:14 GMT
 
*** Ruminant feed ban for cervids in the United States? ***
 
31 Jan 2015 at 20:14 GMT
 
see Singeltary comment ;
 
 
*** Singeltary reply ; Molecular, Biochemical and Genetic Characteristics of BSE in Canada Singeltary reply ;
 
 
*** It also suggests a similar cause or source for atypical BSE in these countries. ***
 
Discussion: The C, L and H type BSE cases in Canada exhibit molecular characteristics similar to those described for classical and atypical BSE cases from Europe and Japan.
 
*** This supports the theory that the importation of BSE contaminated feedstuff is the source of C-type BSE in Canada.
 
*** It also suggests a similar cause or source for atypical BSE in these countries. ***
 
see page 176 of 201 pages...tss
 
 
***atypical spontaneous BSE in France LOL***
 
FRANCE STOPS TESTING FOR MAD COW DISEASE BSE, and here’s why, to many spontaneous events of mad cow disease $$$
 
***so 20 cases of atypical BSE in France, compared to the remaining 40 cases in the remaining 12 Countries, divided by the remaining 12 Countries, about 3+ cases per country, besides Frances 20 cases. you cannot explain this away with any spontaneous BSe. ...TSS
 
Sunday, October 5, 2014
 
France stops BSE testing for Mad Cow Disease
 
 
10 years post mad cow feed ban August 1997
 
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
 
 
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
 
 
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
 
 
New studies on the heat resistance of hamster-adapted scrapie agent: Threshold survival after ashing at 600°C suggests an inorganic template of replication
 
The infectious agents responsible for transmissible spongiform encephalopathy (TSE) are notoriously resistant to most physical and chemical methods used for inactivating pathogens, including heat. It has long been recognized, for example, that boiling is ineffective and that higher temperatures are most efficient when combined with steam under pressure (i.e., autoclaving). As a means of decontamination, dry heat is used only at the extremely high temperatures achieved during incineration, usually in excess of 600°C. It has been assumed, without proof, that incineration totally inactivates the agents of TSE, whether of human or animal origin.
 
 
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production
 
Histochemical analysis of hamster brains inoculated with the solid residue showed typical spongiform degeneration and vacuolation. Re-inoculation of these brains into a new cohort of hamsters led to onset of clinical scrapie symptoms within 75 days, suggesting that the specific infectivity of the prion protein was not changed during the biodiesel process. The biodiesel reaction cannot be considered a viable prion decontamination method for MBM, although we observed increased survival time of hamsters and reduced infectivity greater than 6 log orders in the solid MBM residue. Furthermore, results from our study compare for the first time prion detection by Western Blot versus an infectivity bioassay for analysis of biodiesel reaction products. We could show that biochemical analysis alone is insufficient for detection of prion infectivity after a biodiesel process.
 
 
Detection of protease-resistant cervid prion protein in water from a CWD-endemic area
 
The data presented here demonstrate that sPMCA can detect low levels of PrPCWD in the environment, corroborate previous biological and experimental data suggesting long term persistence of prions in the environment2,3 and imply that PrPCWD accumulation over time may contribute to transmission of CWD in areas where it has been endemic for decades. This work demonstrates the utility of sPMCA to evaluate other environmental water sources for PrPCWD, including smaller bodies of water such as vernal pools and wallows, where large numbers of cervids congregate and into which prions from infected animals may be shed and concentrated to infectious levels.
 
 
A Quantitative Assessment of the Amount of Prion Diverted to Category 1 Materials and Wastewater During Processing
 
Keywords:Abattoir;bovine spongiform encephalopathy;QRA;scrapie;TSE
 
In this article the development and parameterization of a quantitative assessment is described that estimates the amount of TSE infectivity that is present in a whole animal carcass (bovine spongiform encephalopathy [BSE] for cattle and classical/atypical scrapie for sheep and lambs) and the amounts that subsequently fall to the floor during processing at facilities that handle specified risk material (SRM). BSE in cattle was found to contain the most oral doses, with a mean of 9864 BO ID50s (310, 38840) in a whole carcass compared to a mean of 1851 OO ID50s (600, 4070) and 614 OO ID50s (155, 1509) for a sheep infected with classical and atypical scrapie, respectively. Lambs contained the least infectivity with a mean of 251 OO ID50s (83, 548) for classical scrapie and 1 OO ID50s (0.2, 2) for atypical scrapie. The highest amounts of infectivity falling to the floor and entering the drains from slaughtering a whole carcass at SRM facilities were found to be from cattle infected with BSE at rendering and large incineration facilities with 7.4 BO ID50s (0.1, 29), intermediate plants and small incinerators with a mean of 4.5 BO ID50s (0.1, 18), and collection centers, 3.6 BO ID50s (0.1, 14). The lowest amounts entering drains are from lambs infected with classical and atypical scrapie at intermediate plants and atypical scrapie at collection centers with a mean of 3 × 10−7 OO ID50s (2 × 10−8, 1 × 10−6) per carcass. The results of this model provide key inputs for the model in the companion paper published here.
 
 
”The occurrence of CWD must be viewed against the contest of the locations in which it occurred. It was an incidental and unwelcome complication of the respective wildlife research programmes. Despite it’s subsequent recognition as a new disease of cervids, therefore justifying direct investigation, no specific research funding was forthcoming. The USDA veiwed it as a wildlife problem and consequently not their province!” page 26.
 
 
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 study demonstrates susceptibility of adult cattle to oral transmission of classical BSE. ***
 
***our findings suggest that possible transmission risk of H-type BSE to sheep and human. ***
 
P.86: Estimating the risk of transmission of BSE and scrapie to ruminants and humans by protein misfolding cyclic amplification
 
Morikazu Imamura, Naoko Tabeta, Yoshifumi Iwamaru, and Yuichi Murayama National Institute of Animal Health; Tsukuba, Japan
 
To assess the risk of the transmission of ruminant prions to ruminants and humans at the molecular level, we investigated the ability of abnormal prion protein (PrPSc) of typical and atypical BSEs (L-type and H-type) and typical scrapie to convert normal prion protein (PrPC) from bovine, ovine, and human to proteinase K-resistant PrPSc-like form (PrPres) using serial protein misfolding cyclic amplification (PMCA).
 
Six rounds of serial PMCA was performed using 10% brain homogenates from transgenic mice expressing bovine, ovine or human PrPC in combination with PrPSc seed from typical and atypical BSE- or typical scrapie-infected brain homogenates from native host species. In the conventional PMCA, the conversion of PrPC to PrPres was observed only when the species of PrPC source and PrPSc seed matched. However, in the PMCA with supplements (digitonin, synthetic polyA and heparin), both bovine and ovine PrPC were converted by PrPSc from all tested prion strains. On the other hand, human PrPC was converted by PrPSc from typical and H-type BSE in this PMCA condition.
 
Although these results were not compatible with the previous reports describing the lack of transmissibility of H-type BSE to ovine and human transgenic mice, ***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.
 
================
 
 
 
==========================================
 
Wednesday, July 15, 2015
 
Additional BSE TSE prion testing detects pathologic lesion in unusual brain location and PrPsc by PMCA only, how many cases have we missed?
 
 
***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
 
Posted by flounder on 03 Jul 2015 at 16:53 GMT
 
 
*** Needless conflict ***
 
Nature 485, 279–280 (17 May 2012) doi:10.1038/485279b
 
Published online 16 May 2012
 
Terry S. Singeltary Sr. said:
 
I kindly wish to submit the following please ;
 
 
PRION 2015 CONFERENCE FT. COLLINS CWD RISK FACTORS TO HUMANS
 
*** LATE-BREAKING ABSTRACTS PRION 2015 CONFERENCE ***
 
O18
 
Zoonotic Potential of CWD Prions
 
Liuting Qing1, Ignazio Cali1,2, Jue Yuan1, Shenghai Huang3, Diane Kofskey1, Pierluigi Gambetti1, Wenquan Zou1, Qingzhong Kong1 1Case Western Reserve University, Cleveland, Ohio, USA, 2Second University of Naples, Naples, Italy, 3Encore Health Resources, Houston, Texas, USA
 
*** These results indicate that the CWD prion has the potential to infect human CNS and peripheral lymphoid tissues and that there might be asymptomatic human carriers of CWD infection.
 
==================
 
***These results indicate that the CWD prion has the potential to infect human CNS and peripheral lymphoid tissues and that there might be asymptomatic human carriers of CWD infection.***
 
==================
 
P.105: RT-QuIC models trans-species prion transmission
 
Kristen Davenport, Davin Henderson, Candace Mathiason, and Edward Hoover Prion Research Center; Colorado State University; Fort Collins, CO USA
 
Conversely, FSE maintained sufficient BSE characteristics to more efficiently convert bovine rPrP than feline rPrP. Additionally, human rPrP was competent for conversion by CWD and fCWD.
 
***This insinuates that, at the level of protein:protein interactions, the barrier preventing transmission of CWD to humans is less robust than previously estimated.
 
================
 
***This insinuates that, at the level of protein:protein interactions, the barrier preventing transmission of CWD to humans is less robust than previously estimated.***
 
================
 
 
*** PRICE OF CWD TSE PRION POKER GOES UP 2014 ***
 
Transmissible Spongiform Encephalopathy TSE PRION update January 2, 2014
 
*** chronic wasting disease, there was no absolute barrier to conversion of the human prion protein.
 
*** Furthermore, the form of human PrPres produced in this in vitro assay when seeded with CWD, resembles that found in the most common human prion disease, namely sCJD of the MM1 subtype.
 
 
 
*** 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).***
 
 
*** The potential impact of prion diseases on human health was greatly magnified by the recognition that interspecies transfer of BSE to humans by beef ingestion resulted in vCJD. While changes in animal feed constituents and slaughter practices appear to have curtailed vCJD, there is concern that CWD of free-ranging deer and elk in the U.S. might also cross the species barrier. Thus, consuming venison could be a source of human prion disease. Whether BSE and CWD represent interspecies scrapie transfer or are newly arisen prion diseases is unknown. Therefore, the possibility of transmission of prion disease through other food animals cannot be ruled out. There is evidence that vCJD can be transmitted through blood transfusion. There is likely a pool of unknown size of asymptomatic individuals infected with vCJD, and there may be asymptomatic individuals infected with the CWD equivalent. These circumstances represent a potential threat to blood, blood products, and plasma supplies.
 
 
now, let’s see what the authors said about this casual link, personal communications years ago. 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 (216-119-163-189.ipset45.wt.net)
 
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
 
To: rr26k@nih.gov; rrace@niaid.nih.gov; ebb8@CDC.GOV
 
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 ;
 
 
CJD is so rare in people under age 30, one case in a billion (leaving out medical mishaps), that four cases under 30 is "very high," says Colorado neurologist Bosque. "Then, if you add these other two from Wisconsin [cases in the newspaper], six cases of CJD in people associated with venison is very, very high." Only now, with Mary Riley, there are at least seven, and possibly eight, with Steve, her dining companion. "It's not critical mass that matters," however, Belay says. "One case would do it for me." The chance that two people who know each other would both contact CJD, like the two Wisconsin sportsmen, is so unlikely, experts say, it would happen only once in 140 years.
 
Given the incubation period for TSEs in humans, it may require another generation to write the final chapter on CWD in Wisconsin. "Does chronic wasting disease pass into humans? We'll be able to answer that in 2022," says Race. Meanwhile, the state has become part of an immense experiment.
 
 
I urge everyone to watch this video closely...terry
 
*** you can see video here and interview with Jeff's Mom, and scientist telling you to test everything and potential risk factors for humans ***
 
 
Envt.07:
 
Pathological Prion Protein (PrPTSE) in Skeletal Muscles of Farmed and Free Ranging White-Tailed Deer Infected with Chronic Wasting Disease
 
***The presence and seeding activity of PrPTSE in skeletal muscle from CWD-infected cervids suggests prevention of such tissue in the human diet as a precautionary measure for food safety, pending on further clarification of whether CWD may be transmissible to humans.
 
 
Prions in Skeletal Muscles of Deer with Chronic Wasting Disease Rachel C. Angers1,*, Shawn R. Browning1,*,†, Tanya S. Seward2, Christina J. Sigurdson4,‡, Michael W. Miller5, Edward A. Hoover4, Glenn C. Telling1,2,3,§ snip...
 
Abstract The emergence of chronic wasting disease (CWD) in deer and elk in an increasingly wide geographic area, as well as the interspecies transmission of bovine spongiform encephalopathy to humans in the form of variant Creutzfeldt Jakob disease, have raised concerns about the zoonotic potential of CWD. Because meat consumption is the most likely means of exposure, it is important to determine whether skeletal muscle of diseased cervids contains prion infectivity. 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.
 
 
***********CJD REPORT 1994 increased risk for consumption of veal and venison and lamb***********
 
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 ;
 
 
CJD9/10022
 
October 1994
 
Mr R.N. Elmhirst Chairman British Deer Farmers Association Holly Lodge Spencers Lane BerksWell Coventry CV7 7BZ
 
Dear Mr Elmhirst,
 
CREUTZFELDT-JAKOB DISEASE (CJD) SURVEILLANCE UNIT REPORT
 
Thank you for your recent letter concerning the publication of the third annual report from the CJD Surveillance Unit. I am sorry that you are dissatisfied with the way in which this report was published.
 
The Surveillance Unit is a completely independant outside body and the Department of Health is committed to publishing their reports as soon as they become available. In the circumstances it is not the practice to circulate the report for comment since the findings of the report would not be amended. In future we can ensure that the British Deer Farmers Association receives a copy of the report in advance of publication.
 
The Chief Medical Officer has undertaken to keep the public fully informed of the results of any research in respect of CJD. This report was entirely the work of the unit and was produced completely independantly of the the Department.
 
The statistical results reqarding the consumption of venison was put into perspective in the body of the report and was not mentioned at all in the press release. Media attention regarding this report was low key but gave a realistic presentation of the statistical findings of the Unit. This approach to publication was successful in that consumption of venison was highlighted only once by the media ie. in the News at one television proqramme.
 
I believe that a further statement about the report, or indeed statistical links between CJD and consumption of venison, would increase, and quite possibly give damaging credence, to the whole issue. From the low key media reports of which I am aware it seems unlikely that venison consumption will suffer adversely, if at all.
 
 
*** 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).***
 
 
***This information will have a scientific impact since it is the first study that demonstrates the transmission of scrapie to a non-human primate with a close genetic relationship to humans. This information is especially useful to regulatory officials and those involved with risk assessment of the potential transmission of animal prion diseases to humans.
 
***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.
 
 
Tuesday, December 16, 2014
 
*** Evidence for zoonotic potential of ovine scrapie prions
 
Hervé Cassard,1, n1 Juan-Maria Torres,2, n1 Caroline Lacroux,1, Jean-Yves Douet,1, Sylvie L. Benestad,3, Frédéric Lantier,4, Séverine Lugan,1, Isabelle Lantier,4, Pierrette Costes,1, Naima Aron,1, Fabienne Reine,5, Laetitia Herzog,5, Juan-Carlos Espinosa,2, Vincent Beringue5, & Olivier Andréoletti1, Affiliations Contributions Corresponding author Journal name: Nature Communications Volume: 5, Article number: 5821 DOI: doi:10.1038/ncomms6821 Received 07 August 2014 Accepted 10 November 2014 Published 16 December 2014 Article tools Citation Reprints Rights & permissions Article metrics
 
Abstract
 
Although Bovine Spongiform Encephalopathy (BSE) is the cause of variant Creutzfeldt Jakob disease (vCJD) in humans, the zoonotic potential of scrapie prions remains unknown. Mice genetically engineered to overexpress the human ​prion protein (tgHu) have emerged as highly relevant models for gauging the capacity of prions to transmit to humans. These models can propagate human prions without any apparent transmission barrier and have been used used to confirm the zoonotic ability of BSE. Here we show that a panel of sheep scrapie prions transmit to several tgHu mice models with an efficiency comparable to that of cattle BSE. ***The serial transmission of different scrapie isolates in these mice led to the propagation of prions that are phenotypically identical to those causing sporadic CJD (sCJD) in humans. ***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
 
Subject terms: Biological sciences• Medical research At a glance
 
 
see more here ;
 
 
***The serial transmission of different scrapie isolates in these mice led to the propagation of prions that are phenotypically identical to those causing sporadic CJD (sCJD) in humans.***
 
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.***
 
why do we not want to do TSE transmission studies on chimpanzees $
 
5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man. I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.
 
snip...
 
R. BRADLEY
 
 
Friday, August 14, 2015
 
*** Susceptibility of cattle to the agent of chronic wasting disease from elk after intracranial inoculation
 
 
Friday, August 14, 2015
 
Carcass Management During a Mass Animal Health Emergency Draft Programmatic Environmental Impact Statement—August 2015
 
 
Friday, February 05, 2016
 
*** Report of the Committee on Wildlife Diseases FY2015 CWD TSE PRION Detections in Farmed Cervids and Wild ***
 
 
”The occurrence of CWD must be viewed against the contest of the locations in which it occurred. It was an incidental and unwelcome complication of the respective wildlife research programmes. Despite it’s subsequent recognition as a new disease of cervids, therefore justifying direct investigation, no specific research funding was forthcoming. The USDA veiwed it as a wildlife problem and consequently not their province!” page 26.
 
 
In Confidence - Perceptions of unconventional slow virus diseases of animals in the USA - APRIL-MAY 1989 - G A H Wells
 
3. Prof. A. Robertson gave a brief account of BSE. The US approach was to accord it a very low profile indeed. Dr. A Thiermann showed the picture in the ''Independent'' with cattle being incinerated and thought this was a fanatical incident to be avoided in the US at all costs. ...
 
 
AND THEY MEANT IT $$$
 
Saturday, February 6, 2016
 
*** Secretary's Advisory Committee on Animal Health; Meeting [Docket No. APHIS-2016-0007] Singeltary Submission ***
 
 
Subject: CREUTZFELDT JAKOB DISEASE CJD TSE PRION REPORT DECEMBER 14, 2015
 
UNITED STATES OF AMERICA
 
National Prion Disease Pathology Surveillance Center Cases Examined1 (August 25, 2015)
 
Year Total Referrals2 Prion Disease Sporadic Familial Iatrogenic vCJD
 
1996 & earlier
 
56 35 31 4 0 0
 
1997 113 68 59 9 0 0
 
1998 89 53 45 7 1 0
 
1999 121 73 65 7 1 0
 
2000 144 101 89 12 0 0
 
2001 210 118 110 8 0 0
 
2002 242 144 125 17 2 0
 
2003 257 159 138 21 0 0
 
2004 314 180 162 17 0 13
 
2005 328 179 157 21 1 0
 
2006 369 182 163 17 0 24
 
2007 370 206 187 19 0 0
 
2008 387 223 207 16 0 0
 
2009 399 233 212 20 1 0
 
2010 403 247 218 29 0 0
 
2011 393 239 216 23 0 0
 
2012 409 241 218 23 0 0
 
2013 416 257 222 34 1 0
 
2014 355 210 187 21 0 15
 
2015 237 137 118 8 0 0 TOTAL 56126 32857 2929 3338 7 4
 
1 Listed based on the year of death or, if not available, on year of referral;
 
2 Cases with suspected prion disease for which brain tissue was submitted;
 
3 Disease acquired in the United Kingdom;
 
4 Disease acquired in the United Kingdom in one case and in Saudi Arabia in the other;
 
5 Disease possibly acquired in a Middle Eastern or Eastern European country;
 
6 Includes 28 cases in which the diagnosis is pending, and 19 inconclusive cases;
 
7 Includes 12 (11 from 2015) cases with type determination pending in which the diagnosis of vCJD has been excluded. The sporadic cases include 2853 cases of sporadic Creutzfeldt-Jakob disease (sCJD), 54 cases of Variably Protease-Sensitive Prionopathy (VPSPr) and 22 cases of sporadic Fatal Insomnia (sFI).
 
8 Total Excludes 194 familial blood only cases.
 
Rev 8/26/2015
 
 
Confirmed Variant Creutzfeldt-Jakob Disease (variant CJD) Case in Texas in June 2014 confirmed as home grown case
 
Confirmed Variant Creutzfeldt-Jakob Disease (variant CJD) Case in Texas
 
Updated: October 7, 2014
 
CDC and the Texas Department of State Health Services (DSHS) have completed the investigation of the recently reported fourth vCJD case in the United States. It confirmed that the case was in a US citizen born outside the Americas and indicated that the patient's exposure to the BSE/vCJD agent most likely occurred before he moved to the United States; the patient had resided in Kuwait, Russia and Lebanon. The completed investigation did not support the patient's having had extended travel to European countries, including the United Kingdom, or travel to Saudi Arabia. The specific overseas country where this patient’s infection occurred is less clear largely because the investigation did not definitely link him to a country where other known vCJD cases likely had been infected.
 
 
>>>the patient had resided in Kuwait, Russia and Lebanon.
 
>>>The completed investigation did not support the patient's having had extended travel to European countries, including the United Kingdom, or travel to Saudi Arabia.
 
NOW we all know why the state of Texas or the CDC did not want to report this case, because it was a home grown case of nvCJD right here in Texas...tss
 
Monday, June 02, 2014
 
Confirmed Variant CJD Case in Texas
 
 
Sunday, November 23, 2014
 
Confirmed Variant Creutzfeldt-Jakob Disease (variant CJD) Case in Texas in June 2014 confirmed as USA case NOT European
 
 
Monday, November 3, 2014
 
USA CJD TSE PRION UNIT, TEXAS, SURVEILLANCE UPDATE NOVEMBER 2014
 
National Prion Disease Pathology Surveillance Center Cases Examined1 (October 7, 2014)
 
***6 Includes 11 cases in which the diagnosis is pending, and 19 inconclusive cases;
 
***7 Includes 12 (11 from 2014) cases with type determination pending in which the diagnosis of vCJD has been excluded.
 
***The sporadic cases include 2660 cases of sporadic Creutzfeldt-Jakob disease (sCJD),
 
***50 cases of Variably Protease-Sensitive Prionopathy (VPSPr)
 
***and 21 cases of sporadic Fatal Insomnia (sFI).
 
 
Sunday, December 14, 2014
 
ALERT new variant Creutzfeldt Jakob Disease nvCJD or vCJD, sporadic CJD strains, TSE prion aka Mad Cow Disease United States of America Update December 14, 2014 Report
 
 
Sunday, August 11, 2013
 
Creutzfeldt-Jakob Disease CJD cases rising North America updated report August 2013
 
 
Monday, February 24, 2014
 
Sporadic Fatal Insomnia in an Adolescent
 
 
Friday, January 10, 2014
 
*** vpspr, sgss, sffi, TSE, an iatrogenic by-product of gss, ffi, familial type prion disease, what it ???
 
 
>>> We concluded that VPSPr is transmissible; thus, it is an authentic prion disease.
 
Sunday, November 23, 2014
 
Transmission Characteristics of Variably Protease-Sensitive Prionopathy
 
* We concluded that VPSPr is transmissible; thus, it is an authentic prion disease.
 
 
Monday, November 3, 2014
 
The prion protein protease sensitivity, stability and seeding activity in variably protease sensitive prionopathy brain tissue suggests molecular overlaps with sporadic Creutzfeldt-Jakob disease
 
 
 
WHAT about the sporadic CJD TSE proteins ?
 
WE now know that some cases of sporadic CJD are linked to atypical BSE and atypical Scrapie, so why are not MORE concerned about the sporadic CJD, and all it’s sub-types $$$
 
Creutzfeldt-Jakob Disease CJD cases rising North America updated report August 2013
 
*** Creutzfeldt-Jakob Disease CJD cases rising North America with Canada seeing an extreme increase of 48% between 2008 and 2010 ***
 
 
Sunday, October 13, 2013
 
*** CJD TSE Prion Disease Cases in Texas by Year, 2003-2012
 
 
Wednesday, December 11, 2013
 
*** Detection of Infectivity in Blood of Persons with Variant and Sporadic Creutzfeldt-Jakob Disease ***
 
 
07 02:27 AM
 
Terry S. Singeltary Sr. said:
 
re-Evidence for human transmission of amyloid-? pathology and cerebral amyloid angiopathy
 
Nature 525, 247?250 (10 September 2015) doi:10.1038/nature15369 Received 26 April 2015 Accepted 14 August 2015 Published online 09 September 2015 Updated online 11 September 2015 Erratum (October, 2015)
 
 
*** I would kindly like to comment on the Nature Paper, the Lancet reply, and the newspaper articles.
 
snip...see full text ;
 
 
Subject: 1992 IN CONFIDENCE TRANSMISSION OF ALZHEIMER TYPE PLAQUES TO PRIMATES POSSIBILITY ON A TRANSMISSIBLE PRION REMAINS OPEN
 
BSE101/1 0136
 
IN CONFIDENCE
 
CMO
 
From: . Dr J S Metiers DCMO
 
4 November 1992
 
TRANSMISSION OF ALZHEIMER TYPE PLAQUES TO PRIMATES
 
1. Thank you for showing me Diana Dunstan's letter. I am glad that MRC have recognised the public sensitivity of these findings and intend to report them in their proper context. 'This hopefully will avoid misunderstanding and possible distortion by the media to portray the results as having more greater significance than the findings so far justify.
 
2. Using a highly unusual route of transmission (intra-cerebral injection) the researchers have demonstrated the transmission of a pathological process from two cases one of severe Alzheimer's disease the other of Gerstmann-Straussler disease to marmosets. However they have not demonstrated the transmission of either clinical condition as the "animals were behaving normally when killed". As the report emphasises the unanswered question is whether the disease condition would have revealed itself if the marmosets had lived longer. They are planning further research to see if the conditions, as opposed to the partial pathological process, is transmissible.
 
what are the implications for public health?
 
3. The route 'of transmission is very specific and in the natural state of things highly unusual. However it could be argued that the results reveal a potential risk, in that brain tissue from these two patients has been shown to transmit a pathological process. Should therefore brain tissue from such cases be regarded as potentially infective? Pathologists, morticians, neuro surgeons and those assisting at neuro surgical procedures and others coming into contact with "raw" human brain tissue could in theory be at risk. However, on a priori grounds given the highly specific route of transmission in these experiments that risk must be negligible if the usual precautions for handling brain tissue are observed.
 
1
 
92/11.4/1.1
 
BSE101/1 0137
 
4. The other dimension to consider is the public reaction. To some extent the GSS case demonstrates little more than the transmission of BSE to a pig by intra-cerebral injection. If other prion diseases can be transmitted in this way it is little surprise that some pathological findings observed in GSS were also transmissible to a marmoset. But the transmission of features of Alzheimer's pathology is a different matter, given the much greater frequency of this disease and raises the unanswered question whether some cases are the result of a transmissible prion. The only tenable public line will be that "more research is required’’ before that hypothesis could be evaluated. The possibility on a transmissible prion remains open. In the meantime MRC needs carefully to consider the range and sequence of studies needed to follow through from the preliminary observations in these two cases. Not a particularly comfortable message, but until we know more about the causation of Alzheimer's disease the total reassurance is not practical.
 
J S METTERS Room 509 Richmond House Pager No: 081-884 3344 Callsign: DOH 832 llllYc!eS 2 92/11.4/1.2
 
 
>>> The only tenable public line will be that "more research is required’’ <<<
 
>>> possibility on a transmissible prion remains open<<<
 
O.K., so it’s about 23 years later, so somebody please tell me, when is "more research is required’’ enough time for evaluation ?
 
Self-Propagative Replication of Ab Oligomers Suggests Potential Transmissibility in Alzheimer Disease
 
Received July 24, 2014; Accepted September 16, 2014; Published November 3, 2014
 
 
*** Singeltary comment PLoS ***
 
Alzheimer’s disease and Transmissible Spongiform Encephalopathy prion disease, Iatrogenic, what if ?
 
Posted by flounder on 05 Nov 2014 at 21:27 GMT
 
 
SINGELTARY PEER REVIEW
 
Diagnosis and Reporting of Creutzfeldt-Jakob Disease
 
Singeltary, 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.
 
 
26 March 2003
 
Terry S. Singeltary, retired (medically) CJD WATCH
 
I lost my mother to hvCJD (Heidenhain Variant CJD). I would like to comment on the CDC's attempts to monitor the occurrence of emerging forms of CJD. Asante, Collinge et al [1] have reported that BSE transmission to the 129-methionine genotype can lead to an alternate phenotype that is indistinguishable from type 2 PrPSc, the commonest sporadic CJD. However, CJD and all human TSEs are not reportable nationally. CJD and all human TSEs must be made reportable in every state and internationally. I hope that the CDC does not continue to expect us to still believe that the 85%+ of all CJD cases which are sporadic are all spontaneous, without route/source. We have many TSEs in the USA in both animal and man. CWD in deer/elk is spreading rapidly and CWD does transmit to mink, ferret, cattle, and squirrel monkey by intracerebral inoculation. With the known incubation periods in other TSEs, oral transmission studies of CWD may take much longer. Every victim/family of CJD/TSEs should be asked about route and source of this agent. To prolong this will only spread the agent and needlessly expose others. In light of the findings of Asante and Collinge et al, there should be drastic measures to safeguard the medical and surgical arena from sporadic CJDs and all human TSEs. I only ponder how many sporadic CJDs in the USA are type 2 PrPSc?
 
 
The Lancet Infectious Diseases, Volume 3, Issue 8, Page 463, August 2003 doi:10.1016/S1473-3099(03)00715-1Cite or Link Using DOI
 
Tracking spongiform encephalopathies in North America
 
Original
 
Xavier Bosch
 
“My name is Terry S Singeltary Sr, and I live in Bacliff, Texas. I lost my mom to hvCJD (Heidenhain variant CJD) and have been searching for answers ever since. What I have found is that we have not been told the truth. CWD in deer and elk is a small portion of a much bigger problem.” 49-year—old Singeltary is one of a number of people who have remained largely unsatisfied after being told that a close relative died from a rapidly progressive dementia compatible with spontaneous Creutzfeldt—Jakob ...
 
 
Suspect symptoms
 
What if you can catch old-fashioned CJD by eating meat from a sheep infected with scrapie?
 
28 Mar 01
 
Most doctors believe that sCJD is caused by a prion protein deforming by chance into a killer. But Singeltary thinks otherwise. He is one of a number of campaigners who say that some sCJD, like the variant CJD related to BSE, is caused by eating meat from infected animals. Their suspicions have focused on sheep carrying scrapie, a BSE-like disease that is widespread in flocks across Europe and North America. Now scientists in France have stumbled across new evidence that adds weight to the campaigners' fears. To their complete surprise, the researchers found that one strain of scrapie causes the same brain damage in mice as sCJD.
 
"This means we cannot rule out that at least some sCJD may be caused by some strains of scrapie," says team member Jean-Philippe Deslys of the French Atomic Energy Commission's medical research laboratory in Fontenay-aux-Roses, south-west of Paris. Hans Kretschmar of the University of Göttingen, who coordinates CJD surveillance in Germany, is so concerned by the findings that he now wants to trawl back through past sCJD cases to see if any might have been caused by eating infected mutton or lamb...
 
 
2 January 2000
 
British Medical Journal
 
U.S. Scientist should be concerned with a CJD epidemic in the U.S., as well
 
 
15 November 1999
 
British Medical Journal
 
vCJD in the USA * BSE in U.S.
 
 
 
Terry S. Singeltary Sr. flounder9@verizon.net



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