USDA
National Program 103 ANIMAL HEALTH ACCOMPLISHMENT REPORT 2011-2015
March 2015
Component 7: Transmissible Spongiform Encephalopathies
Rationale for the research
Scrapie of sheep, bovine spongiform encephalopathy (BSE) of cattle, chronic
wasting disease (CWD) of deer and elk, and variant Creutzfeldt-Jacob disease
(vCJD) of humans are all fatal neurodegenerative disorders classified as
transmissible spongiform encephalopathies (TSEs). There are no effective
treatments or cure. The origin of TSEs has yet to be determined but scientific
evidence indicates that the causal agents are abnormal prion proteins that
induce a catalytic conversion of the normal host protein into an abnormal form.
The abnormal prion proteins are transmissible and in most cases appear to be
resistant to degradation. The discovery in 1996 that BSE of cattle is the cause
of vCJD in people represented an unforeseen emerging zoonosis. That discovery
has raised concern in the public health community that other TSEs such as CWD
could evolve to cause disease in people. Although there is no evidence that CWD
is zoonotic, TSEs have now been shown to be able to cross the species barrier,
both experimentally and under natural conditions.
To date, only four cases of BSE have been found in the United States. The
first case was found December 2003 in a cow imported from Canada and is
estimated to have cost the U.S. beef industry $3.2 billion to $4.7 billion from
the loss of beef and offal exports. The three subsequent cases were in cows born
and raised in the United States. The first United States indigenous case was
found in a downer cow in Texas, November 2004; the second indigenous cow was
found on a farm in Alabama, March 2006; the third indigenous case was recently
found on a dairy farm in California, April 2012. The finding of three indigenous
cases of BSE, and the number of scrapie and CWD cases reported annually in the
United States continues to raise concerns about the public health risks of
animal TSEs.
Despite being caused by misfolding of a host encoded protein, it is now
known that BSE exists as more than one strain. The form first identified has
been termed classical BSE. This is the form associated with the feed-borne
epizootic in the United Kingdom. More recently, two other forms have been
identified and can be broadly referred to as atypical BSE, or specifically
defined as High-type (H-type) or Low-type (L-type) BSE based upon their
migration pattern relative to classical BSE on a Western blot. Neither H-type
nor L-type BSE is associated with the feed-borne epizootic. Based on various
forms of evidence, H-type and L-type BSE are generally believed to be
spontaneous in nature rather than feed-borne, as is the case for classical BSE.
The three indigenous U.S. BSE cases were reported as “atypical.” The first two
indigenous BSE cases reported in 2004 and 2006 were reported as H-Type BSE,
while the case in 2012 an L-type BSE. ARS scientists have made significant
contributions to the understanding of the atypical H-Type BSE cases found in the
United States. ARS identified the first genetic case of BSE, and showed that it
is a heritable polymorphism. ARS scientists have also contributed to the
understanding of atypical BSE as a potential spontaneous TSE in cattle. This
information supports, for the first time, the presence of three different
etiologies (spontaneous/sporadic, genetic, and infectious/feedborne) of BSE in
cattle. Previously, only humans were known to have three separate etiologies for
TSEs. In collaboration with APHIS and a team of Italian researchers,
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ARS has shown that the United States and Italian diagnostic techniques are
equivalent in identifying classical, H-type, and L-type BSE, an important
contribution that helped identify the April 2012 atypical L-type BSE case in
California. Scrapie, the TSE of sheep and goats, is the subject of an intensive
eradication effort conducted by a federal-state-industry partnership. From FY
2003 through FY 2013, scrapie prevalence declined by 90 percent. The eradication
program includes diagnostic testing using a platform and antibodies developed by
ARS and a voluntary selective breeding program using data developed by ARS.
Scrapie in goats is less well understood and ARS has contributed to improved
diagnostics and basic studies on genetic resistance to TSEs of goats. Chronic
wasting disease, the TSE of wild and captive deer and elk, is also monitored by
live animal and post-mortem tests developed by ARS in collaboration with a
network of wildlife agencies and university partners.
Stakeholders at the September 2011 Animal Health Planning Workshop
representing the wildlife, sheep, and goat industries ranked TSE research as
their 1st priority; representatives of the beef industry ranked TSE research as
their 6th priority. Diseases in Component 7 include classical and atypical BSE,
scrapie, and CWD.
Research Needs:
The Institute of Medicine of the National Academies published a guidance
document November 2003 calling for a National Prion Research Program (Advancing
Prion Science: Guidance for the National Prion Research Program – free download
available from the National Academies Press at http://www.nap.edu/catalog.php?record_id=10862).
Key recommendations from the National Academies report included funding
basic research to elucidate:
1) the structural features of prions;
2) the molecular mechanisms of prion replication;
3) the mechanisms of pathogenesis of TSEs; and
4) the physiological function of the normal prion protein. In addition, the
National Academies report recommended a comprehensive applied research program
in diagnostics, testing blood for evidence of TSEs, epidemiological studies to
monitor the occurrence of TSEs in human and animals, and research that will lead
to strategies to prevent and treat TSEs.
The White House Office of Science and Technology Policy (OSTP) created a
federal Interagency Working Group (IWG) on Prion Science in September 2004. ARS
and the NIH co-led the IWG with participation Food and Drug Administration,
APHIS, Centers for Disease Control and Prevention, Department of Defense, and
Environmental Protection Agency. The working group determined that although
significant scientific advances had been made, the research conducted to date
had yet to deliver many of the concrete solutions needed to safeguard people and
animals from these devastating diseases. A critical concern was the potential
for environmental, genetic, or iatrogenic events that could lead to new variant
TSEs that are infectious and zoonotic (transmissible from animals to humans).
The following six priorities were selected by the IWG on Prion Science to
maximize the impact of a National Prion Research Program:
• Nature and origin of prion agents
• Pathobiology of prion strains
• Determinants of transmissibility and epidemiology
• Genetics of disease susceptibility
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• Diagnostics, detection, and surveillance
• Prevention and treatment
These six interrelated priorities represent areas with critical gaps in our
knowledge base. They were selected with the aim of establishing strategic
collaborations that will produce benefits by aligning core competencies across
federal agencies.
Because TSE clinical studies in livestock and cervids require several years
to reach an end-point, the associated expenses and resources needed to implement
a research program, and the need for multidisciplinary research teams, ARS
integrated its prion research laboratories located in Ames, Iowa, Pullman,
Washington, and Albany, California, into a national coordinated research program
in 2004. ARS focused its core competencies and the available resources of its
national coordinated research program on six research needs: 1) understand
infectivity, tissues tropism, and pathogenesis; 2) identify determinants of host
range specificity; 3) understand the molecular mechanisms of prion replication;
4) strain characterization and determinants of virulence; 5) develop ante-mortem
(live) pre-clinical animal tests; and 6) discover cost effective methods of
prion inactivation. These research needs were the basis for determining the
anticipated products that are expected from the research, and that now serve to
help measure the national program’s progress during the last five years in
meeting the needs of animal producers, researchers, and action and regulatory
agencies. The following list of anticipated products from the Action Plan is
followed by the expected impact of the research and a sampling of relevant
accomplishments.
Anticipated Products In Action Plan:
• Sensitive and specific ante-mortem tests that are rapid and
scalable.
• Establish the biochemical, pathological, and epidemiological profile of
atypical TSE strains and unusual isomers of the prion protein.
• Determine the pathogenesis of TSEs, including establishing route(s) of
prion migration in the host, amplification of the agent, and disease
expression.
• Conduct interspecies transmission studies to determine the host range
specificity and resulting risk of TSEs to other animal species.
• Enhanced rapid methods of agent detection to protect the human
environment.
• Cost effective methods of inactivating TSE agents.
• Identify and characterize genotypic variations and functional genomic
mechanisms associated with disease susceptibility or resistance.
Impact:
The impact of the research included scientific information to enable
regulatory and action agencies to promulgate science-based control programs. The
development of diagnostics and countermeasures has enhanced current federal and
state control and eradication programs for scrapie and CWD and will continue to
enable the prevention and containment of future occurrences of BSE.
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COMPONENT 7: SELECTED ACCOMPLISHMENTS
Problem Statement 7A: Nature and Origin of Prion Agents
Experimental Interspecies Transmission Studies of Transmissible Spongiform
Encephalopathies in Cattle.
Experimental cross-species transmission of TSE agents provides valuable
information for potential host ranges of known TSEs. Some interspecies
transmission studies have been conducted by inoculating disease-causing prions
intracerebrally (IC) rather than orally; the latter is generally effective in
intraspecies transmission studies and is considered a natural route by which
animals acquire TSEs. The "species barrier" concept for TSEs resulted from
unsuccessful interspecies oral transmission attempts. Oral inoculation of prions
mimics the natural disease pathogenesis route whereas IC inoculation is rather
artificial; however, it is very efficient since it requires smaller dosage of
inoculum, and typically results in higher attack rates and reduces incubation
time compared to oral transmission. A species resistant to a TSE by IC
inoculation would have negligible potential for successful oral transmission. To
date, results indicate that cattle are susceptible to IC inoculation of scrapie,
transmissible mink encephalopathy (TME), and CWD but it is only when inoculated
with TME do they develop spongiform lesions or clinical disease similar to BSE.
Importantly, cattle are resistant to oral transmission of scrapie or CWD;
susceptibility of cattle to oral transmission of TME has not yet
determined.
Scientific Publication
Hamir A.N., Kehrli M.E. Jr., Kunkle R.A., Greenlee J.J., Nicholson E.M.,
Richt J.A., Miller J.M., Cutlip R.C. 2011. Experimental interspecies
transmission studies of the transmissible spongiform encephalopathies to cattle:
comparison to bovine spongiform encephalopathy in cattle. J Vet Diagn Invest.
2011 May;23(3):407-20.
Experimental Transmission of Chronic Wasting Disease from Elk and
White-tailed deer to Fallow Deer and Reindeer.
Final observations on experimental transmission of chronic wasting disease
(CWD) from elk and white-tailed deer to fallow deer from a 5-year study were
reported. During the study, 13 fawns were inoculated intracerebrally with
CWD-infected brain material from white-tailed deer and 3 other fawns were kept
as uninoculated controls. Animals were euthanized at 7, 24, 26, months
post-inoculation (MPI), and between 29-37 and 51-60 MPI. Only five of the deer
kept between 51 and 60 MPI became sick and were euthanized. Microscopic lesions
of spongiform encephalopathy were observed in only these five animals; however,
abnormal prions were detected in tissues of the central nervous system by
immunohistochemistry, Western blot, and by a commercial rapid test in all
animals that survived beyond 24 months post-infection. This study demonstrated
that intracerebrally inoculated fallow deer not only amplify CWD prions, but
also develop lesions of spongiform encephalopathy. These results provide
information on the potential risk of CWD transmission across different cervid
species, and contributes to understanding CWD transmission in wild and captive
cervids. CWD in reindeer is a serious threat to the livelihood and cultural
integrity of indigenous peoples of the northern region of North America. The
susceptibility of the species was established through an oral challenge,
representing the presumed natural route of infection in the wild.
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Antemortem diagnosis and postmortem confirmatory testing demonstrated that
two of three reindeer challenged with white tailed deer CWD developed the
disease within 2 years. The third reindeer in this group, and 3 reindeer orally
inoculated with CWD of elk origin, failed to develop CWD. These 4 animals all
had a polymorphism in the prion gene encoding a novel change at position 138.
These findings demonstrate that (i) a sub-population of reindeer are susceptible
to CWD by oral inoculation implicating the potential for transmission to other
Rangifer species, and (ii) certain reindeer PRNP polymorphisms may be protective
against CWD infection.
Scientific Publications
Hamir A.N., Greenlee J.J., Nicholson E.M., Kunkle R.A., Richt J.A., Miller
J.M., Hall M. 2011. Experimental transmission of chronic wasting disease (CWD)
from elk and white-tailed deer to fallow deer by intracerebral route: final
report. Can J Vet Res. 2011 Apr;75(2):152-6.
Mitchell, G.B., Sigurdson, C.J., O'Rourke, K.I., Algire, J., Harrington,
N.P., Walther, I., Spraker, T.R., Balachandran, A. 2012. Experimental oral
transmission of chronic wasting disease to reindeer (Rangifer tarandus
tarandus). PLoS One. 7:e39055.
Problem Statement 7B: Pathobiology of Prion Strains
Stability Profiling of Typical and Atypical Transmissible Spongiform
Encephalopathy (TSE) Isolates.
Scientists at the National Animal Disease Center, Ames, Iowa, developed a
method for the rapid evaluation of the stability of the disease-associated form
of the prion protein (PrPSc). This method was applied to isolates of sheep
scrapie and bovine spongiform encephalopathy (BSE). Comparisons between isolates
and hosts with different genotypes were evaluated for both sheep and cattle. For
sheep scrapie, results showed that the stability of PrPSc correlates with the
disease incubation time in the animal and that the process known as strain
stabilization, whereby a TSE is passed serially through a host species, does not
alter the physical properties of the infectious agent. Thus, changes in disease
incubation time that are known to occur are likely due to changes such as the
infectious dose of the inoculating material. For BSE, ARS scientists showed that
the stability of cattle PrPSc, as defined by resistance to denaturant unfolding
of the fibrils, is largely invariant with the exception of atypical H-type BSE,
which exhibits a higher stability. The stability of a genetic form of BSE (E211K
BSE) is consistent with its previous assignment as an H-type strain. In addition
to the increased knowledge with regard to strains of scrapie in sheep and BSE in
cattle, the methodologies used here can also be applied to research on other
species (such as goats, deer, and elk) to improve our understanding of the
properties of TSE strains of scrapie, BSE, and CWD in natural hosts.
Scientific publications
Vrentas, C.E., Greenlee, J.J., Tatum, T.L., Nicholson, E.M. 2012.
Relationships between PrPSc stability and incubation time for United States
scrapie isolates in a natural host system. PLoS ONE. 7(8):e4306
Vrentas, C.E., Greenlee, J.J., Baron, T., Caramelli, M., Czub, S.,
Nicholson, E.M. Stability properties of PrPSc from cattle with experimental
transmissible spongiform encephalopathies. BMC Vet Res. 2013; 9: 167.
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Clinical and Pathologic Features of a Genetic Case of BSE.
The majority of bovine spongiform encephalopathy (BSE) cases have been
ascribed to the classical form of the disease. H-type and L-type BSE cases have
atypical molecular profiles relative to classical BSE and are thought to arise
spontaneously. However, one case of H-type BSE was associated with a heritable
E211K mutation in the prion protein gene. Scientists at the National Animal
Disease Center, Ames, Iowa, conducted a study to evaluate the transmission of
this unique isolate of H-type BSE when inoculated into a calf of the same
genotype by the intracranial route. Electroretinograms were used to demonstrate
preclinical deficits in retinal function and optical coherence tomography was
used to demonstrate an antemortem decrease in retinal thickness. The calf
rapidly progressed to clinical disease (9.4 months). Widespread distribution of
abnormal prion protein was demonstrated within neural tissues by western blot
and immunohistochemistry. While this isolate is categorized as BSE-H due to a
higher molecular mass of the unglycosylated PrPSc isoform, differences in the
specific western blot pattern indicate it is unique from other described cases
of BSE-H. This work demonstrates that this isolate is transmissible, has a BSE-H
phenotype when transmitted to cattle with the K211 polymorphism, and has
molecular features that distinguish it from other cases of BSE-H described in
the literature.
Scientific publication
Greenlee, J.J., Smith, J.D., West Greenlee, M.H., Nicholson, E.M. Clinical
and pathologic features of H-type bovine spongiform encephalopathy associated
with E211K prion protein polymorphism. PLoS One. 2012;7(6):e38678. Problem
Statement 7C: Determinants of Transmissibility and Epidemiology
Accumulation of Prion Scrapie in the Placentas of Goats.
Domestic goats are a natural and experimental host of scrapie and bovine
spongiform encephalopathy. Goats are also susceptible to experimental infection
with Chronic Wasting Disease and Creutzfeldt Jakob disease. Distribution of
prion scrapie is similar in the tissues of scrapie-infected sheep and goats but
no data are available on the potential shedding of the agent through the
placenta, the presumed route of transmission of ovine scrapie. ARS scientists in
Pullman, Washington, studied the accumulation of prion scrapie in the placentas
of goats with naturally acquired classical scrapie in comparison to field cases
of classical ovine scrapie. The results of these studies showed that prion
scrapie accumulates in the shed placentas of goats with naturally acquired
scrapie. Although these levels were low in most caprine samples, the caprine
placenta may contribute to prion contamination of kidding facilities and
transmission to co-housed sheep or goats.
Scientific Publication
O'Rourke K.I., Zhuang D., Truscott T.C., Yan H., Schneider D.A. 2011.
Sparse PrP(Sc) accumulation in the placentas of goats with naturally acquired
scrapie. BMC Vet Res.1; 7:7.
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Problem Statement 7D: Genetics of Prion Disease Susceptibility
Pathologic and Biochemical Characterization of a Genetic Gorm of Bovine
Spongiform Encephalopathy (BSE).
Transmissible spongiform encephalopathies (TSE) such as BSE are
characterized by a novel transmissible “infectious” protein called a prion that
converts the cellular form of the prion protein (PrPc), normally expressed by
many cells in the body, to a misfolded, disease-associated form (PrPd) that
causes pathological lesions in the central nervous system. The complete
pathologic and biochemical features of a genetic form of BSE were defined and
reported for the first time by ARS scientists at the National Animal Disease
Center, Ames, Iowa. The genetic form of BSE is analogous to the most prevalent
hereditary form of human TSE. Heritable BSE along with spontaneous BSE forms are
also referred to as atypical BSE cases which have important implications in that
they are not associated with the feedborne epidemic of classical BSE first
recognized in the United Kingdom in the 1980s. Atypical BSE cases emphasize the
need to maintain the specified risk material ruminant feed ban as a
science-based policy to prevent a feedborne epidemic from developing; the
feedborne nature of the classical BSE epidemic has been demonstrated to
negatively impact export markets in various countries around the world, whereas
atypical BSE does not connote the same concern.
Scientific Publication
Greenlee, J.J., Smith, J.D., West Greenlee, M.H., Nicholson, E.M. 2012.
Clinical and pathologic features of H-type bovine spongiform encephalopathy
associated with E211K prion protein polymorphism. PLoS ONE. 7(6):e38678.
A Genetic Marker Associated with Resistance to Scrapie.
The amino acid, lysine, at position 171 of the sheep prion protein delays
development of scrapie. ARS scientists demonstrated the effect of the amino acid
lysine at position 171 of the sheep prion protein on susceptibility to scrapie,
a transmissible spongiform encephalopathy of sheep. Amino acid differences in
the prion protein are known to play a major role in scrapie susceptibility in
sheep and these genetic differences are utilized in the strategy to remove
scrapie from our nation's sheep flock. Natural scrapie had previously only been
described in one sheep with lysine at position 171 of the prion protein, hence
not enough information was available from natural cases to determine the effect
of lysine at position 171 on scrapie susceptibility. ARS scientists at the
National Animal Disease Center, Ames, Iowa, demonstrated that sheep with a prion
protein containing lysine at position 171 are susceptible to scrapie but have a
prolonged scrapie incubation period, and that the abnormal prion protein
accumulates throughout the central nervous system and lymphoid organs. Because
sheep with lysine at prion amino acid position 171 develop scrapie at a slower
rate than other known susceptible genotypes this information is critical to
sheep breeders that want to eradicate genotypes susceptible to scrapie.
Scientific Publication
Greenlee, J.J., Zhang, Xia, Nicholson, E.M., Kunkle, R.A., Hamir, A.N.
2012. Prolonged incubation time in sheep with prion protein containing lysine at
position 171. Journal of Veterinary Diagnostic Investigation.
24(3):554-558.
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Prolonged Scrapie Incubation in Goats Linked to Two Genetic Markers.
ARS scientists performed the first oral scrapie challenge of goats
heterozygous for two PrPc polymorphisms (commonly referred to as genetic
variation or alleles) of particular interest to scrapie susceptibility. Scrapie
eradication in sheep is based in part on strong genetic resistance to classical
scrapie. Goats may serve as a scrapie reservoir but there has been limited
experimental inoculation to confirm strong genetic resistance in goats. The
results confirmed that goats singly heterozygous at the two PrPc alleles (S142
or K222) have greatly extended incubation times, indicating a need in
scrapie-eradication programs for longer trace-back histories for goats bearing
these alleles. Also indicated is a need to assess goats singly homozygous for
either of these alleles for enhanced resistance to scrapie infection.
Scientific Publication White, S.N., Reynolds, J.O., Waldron, D.F.,
Schneider, D.A. & O'Rourke, K.I. 2012. Extended scrapie incubation time in
goats singly heterozygous for PRNP S146 or K222. Gene 501:49-51.
Problem Statement 7E: Diagnostics, Detection, and Surveillance
Development of a Rapid Method for Detection of Disease-associated
Prions.
A method for the detection of abnormal prions (PrPSc) in formalin-fixed
paraffin-embedded tissue by ELISA has been developed and described by ARS
scientists at the National Animal Disease Center, Ames, Iowa. Methods for
diagnosis of transmissible spongiform encephalopathies (TSEs) in cattle, sheep
and cervids have traditionally depended on the availability of both frozen fresh
and formalin-fixed tissues. However, in many diagnostic sample submissions only
formalin-fixed samples have been available for TSE diagnosis, a situation that
previously precluded analysis by rapid diagnostic procedures such as ELISA. This
work describes a method suitable for extraction of the PrPSc from formalin-fixed
paraffin-embedded tissue for detection by ELISA. This represents a significant
advancement for diagnostic laboratories and provides a rapid alternative method
for TSE detection beyond immunohistochemistry (IHC).
Scientific Publication
Nicholson, E.M., Greenlee, J.J., Hamir, A.N. 2011. PrPSc detection in
formalin-fixed paraffin-embedded tissue by ELISA. BMC Research Notes.
4(1):432.
Control of Chronic Wasting Disease (CWD) in Deer and Elk through Live
Animal Diagnosis and Genetic Selection. Elk and deer are farmed in many parts of
the United States. As CWD in the wild population continues to spread, the
ability to monitor the disease in free ranging cervids and perform surveillance
on farmed deer and elk are critical for the survival of the captive cervid
industry. Using the test platform developed for sheep, federal and state
laboratories perform tissue based testing on clinical suspects, slaughter
samples, and hunter harvested deer and elk. Coupled with an understanding of the
role of prion genotypes in prolonging incubation time, the regulatory groups
have an arsenal of methods for CWD management suitable in their regions.
Scientific publications
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Monello, R.J., Powers, J.G., Hobbs, N.T., Spraker, T.R., O'Rourke, K.I.,
Wild, M.A. 2013. Efficacy of antemortem rectal biopsies to diagnose and estimate
prevalence of chronic wasting disease in free-ranging cow elk (Cervus elaphus
nelsoni). Journal of Wildlife Diseases. 49:270-278.
Thomsen, B.V., Schneider, D.A., O'Rourke, K.I., Gidlewski, T., McLane, J.,
Allen, R.W., McIsaac, A.A., Mitchell, G.B., Keane, D.P., Spraker, T.R.,
Balachandran, A. 2012.
Diagnostic accuracy of rectal mucosa biopsy testing for chronic wasting
disease within white-tailed deer (Odocoileus virginianus) herds in North
America: Effects of age, sex, polymorphism at PRNP codon 96, and disease
progression. Journal of Veterinary Diagnostic Investigation. 24:878-887.
Confirmatory Laboratory Tests to Detect Classical and Atypical BSE
Forms.
ARS scientists in Ames, Iowa, obtained brain samples from cases of United
States and Italian Classical (C-) type, U.S. High (H-) type, and an Italian Low
(L-) type BSE to compare the ability of two sets of immunohistochemical (IHC)
and Western blot (WB) confirmatory protocols to detect C- and atypical (L- and
H-type) BSE forms. The study showed that the IHC and WB BSE confirmatory
protocols were equally able to recognize C-, L- and H-type BSE forms and to
discriminate between their different immunohistochemical and molecular
phenotypes. Importantly, for the first time, one of the two sets of BSE
confirmatory protocols proved effective in identifying the L-type BSE form. This
finding helped validate the suitability of the BSE confirmatory tests for BSE
surveillance currently in place in the United States.
Scientific Publication
Porcario C., Hall SM, Martucci F., Corona C., Iulini B., Perazzini A.Z.,
Acutis P., Hamir A.N., Loiacono C.M., Greenlee J.J., Richt J.A., Caramelli M.,
Casalone C. 2011.
Evaluation of two sets of immunohistochemical and Western blot confirmatory
methods in the detection of typical and atypical BSE cases. BMC Res Notes. 2011
Sep 29;4:376.
Prion Infectivity in Scrapie-infected Sheep and Goat Blood. ARS researchers
at the Animal Disease Research Unit in Pullman, Washington, have identified the
components of sheep’s and goat’s blood that carry prion infectivity by using the
sensitive technique of transfusion bioassay. The presence of infectious scrapie
prions in the blood indicates the possibility of developing a blood-based
diagnostic test but currently available immunoassays do not appear to be
sensitive enough for robust detection in samples of whole blood. The insights
gained are an important step toward optimizing the isolation of the blood
components most relevant to early disease detection by immunoassay in both sheep
and goats.
Scientific Publications Dassanayake R.P., Schneider D.A., Truscott T.C.,
Young A.J., Zhuang D, ORourke K.I. 2011 Classical scrapie prions in ovine blood
are associated with B lymphocytes and platelet rich plasma. BioMed Central (BMC)
Veterinary Research. 7:75.
Dassanayake, R.P., Schneider, D.A., Herrmann-Hoesing, L.M., Truscott, T.C.,
Davis, W.C., O'Rourke, K.I. 2012. Cell-surface expression of PrPC and the
presence of scrapie prions in the blood of goats. J Gen Virol.
93(5):1127-1131.
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Detection of Disease Associated Prion Protein in Retina of Sheep and Cattle
using a Commercially Available Diagnostic Kit.
Scientists from the National Animal Disease Center, Ames, Iowa, evaluated
samples from experimental animal challenge studies to assess the usefulness of
retina samples for detection of prion positive animals, using a commercially
available enzyme immunoassay (EIA) intended for rapid identification of sheep
and cattle with transmissible spongiform encephalopathies (TSEs). Retina sample
EIA results were in agreement with results of brainstem sample EIA or
confirmatory assay results for negative control animals and TSE-inoculated
animals with clinical signs of disease. However, TSE-inoculated animals with
positive confirmatory assay results that did not have clinical signs of disease
had negative retina sample EIA results. Retina sample EIA results were in
agreement with brainstem sample immunohistochemistry results for 4
TSE-inoculated sheep with negative retropharyngeal lymph node EIA results.
Results from this study suggest that retina samples may be useful for rapid EIA
screening of animals with neurologic signs to detect TSEs.
Scientific publication
Smith, J.D., Greenlee, J.J. Detection of misfolded prion protein in retina
samples of sheep and cattle by use of a commercially available enzyme
immunoassay. Am J Vet Res. 2014; 75(3): 268-72.
Problem Statement 7F: Prevention and Treatment
Methods for Inactivation of the TSE Agent
Prions demonstrate an unusual resistance to methods effective at
inactivating conventional microorganisms, and the only means by which successful
inactivation can be validated is by a bioassay in animals. The difficulty in
inactivation and in developing methods to test and validate the inactivation of
TSE agents has resulted in a very tangible and difficult challenge for the
medical and veterinary communities, as well as animal agriculture and related
industries. To address both problems, ARS scientists at the National Animal
Disease Center, Ames, Iowa, have evaluated a means by which the harsh chemical
treatment to inactivate prions can be removed prior to conducting the bioassay,
and they also evaluated milder treatments in a combinatorial
approach. Through these efforts, acetone was shown to suitably precipitate
misfolding prion proteins (PrPSc), allowing the inoculation of animals for
bioassay without the large dilution of infectivity usually required to dilute
harsh chemicals before the test material can be inoculated in animals. This
method now allows researchers to more readily assess inactivation approaches,
providing an important tool for further study of TSE agent inactivation. The
assessment of milder treatments used in combination showed that such an approach
can markedly reduce TSE infectivity in a manner greater than individual
treatments alone. This indicated that suitable approaches for TSE agent
inactivation may be developed using combinations of treatments that are alone
not sufficient to inactivate the TSE agent.
Scientific publications
Smith, J.D., Nicholson, E.M., Greenlee, J.J. Evaluation of a combinatorial
approach to prion inactivation using an oxidizing agent, SDS, and proteinase K.
BMC Vet Res. 2013; 9: 151.
ARS NP 103 Accomplishment Report 2011-2015 – Component 7
83
Smith, J.D., Greenlee, J.J., Foster, G.H., and Nicholson, E.M. Acetone
precipitation of the scrapie agent results in successful recovery of PrPSc but
decreased infectivity. J Agric Food Chem. 2012; 60: 4758-4762.
84
Appendices
***AN INDEPENDENT REVIEW OF THE ABOVE REPORT, from the other side of the
fence, the rest of the scientific facts, and what the potential there from mean.
first, a further review of the said scientific findings above;
Research Project: Mitigating the Risk of Transmission and Environmental
Contamination of Transmissible Spongiform Encephalopathies
Location: Animal Diseases Research
2015 Annual Report
1a.Objectives (from AD-416):
Objective 1: Determine whether goats are a transmission reservoir for ovine
scrapie by developing and validating diagnostic methods for detecting goat
scrapie. Determine the genetic predisposition and transmission route(s) of goat
scrapie.
Subobjective 1.1: Improve eradication efforts by developing improved
methods for antemortem scrapie diagnosis.
Subobjective 1.2: Determine if placenta and milk from goats are potential
sources of scrapie to sheep.
Objective 2: Develop methods to mitigate infectivity of soil-associated
prions by screening soil microbes for potential candidates for bioremediation.
1b.Approach (from AD-416): Scrapie is a complex and rare disorder affecting
outbred farm animals held under a wide variety of husbandry conditions and
exposed to an agent for which the transmissible and pathogenic events remain
largely unknown. The work described in the research plan is an extension of the
previous highly productive studies by this research group, addressing the need
for implementation of federal regulations based on the best available science,
often in the face of relatively small sample numbers in the natural host. The
work includes development of specific management and diagnostic tools and is
presented as an integrated series of research objectives. This approach was
selected over a hypothesis based approach. After consulting Glass and Hall, the
group determined that the work presented in the following plan was best
represented by goal statements rather than hypotheses because the work increases
the density of data necessary for progress and for support of current and
proposed federal regulations. This project addresses only scrapie, the TSE of
sheep and goats. Chronic wasting disease (CWD) is the TSE of North America
cervids (deer and elk). ***No live animal work with CWD is included in this
project plan since CWD is not endemic in Washington State, the disease appears
to be highly communicable, the modes of transmission are unknown, and we do not
have suitable biocontainment facilities to conduct CWD studies in large animals.
3.Progress Report: The National Scrapie Eradication program in the U.S. is
conducted by the state and federal animal disease health regulatory agencies,
with research support by ARS and several land grant universities, in a joint
endeavor with the sheep and goat industries. The comprehensive program of animal
identification, surveillance and genetic selection has resulted in a decrease of
scrapie prevalence by 88%. As prevalence falls, remaining potential sources of
infection will be monitored. The transmissible spongiform encephalopathies (TSE)
project at the Animal Disease Research Unit, Pullman, Washington, includes an
integrated examination of modes of transmission (both intraspecies and
interspecies), diagnostic test development and refinement, and delineation of
species-specific and genetically controlled differences in pathogenesis. In
FY15, progress was reported in each of these research areas.
Objective 1: Transmission of scrapie by placenta, blood and milk. Exposure
of the newborn lamb or kid to infectious prions shed by the postparturient
ewe/doe is probably the most efficient route of transmission in the field. Our
earlier work demonstrated the role of fetal genotype on transmission by the
ovine placenta. In this Fiscal Year (FY), we completed a study demonstrating
that the caprine placenta, while containing sparse amounts of detectable PrP-Sc,
is infectious to lambs and kids by oral exposure. Experimental oral exposure of
lambs and kids to milk from infected does during the first 2 to 3 days of life
was performed last year and the recipient animals are monitored for evidence of
disease. With an incubation period of 24-36 months, the study is expected to
yield useful information in FY16. These studies of experimental disease are
complemented by ongoing observations on transmission in our mixed herd of
infected goats and sheep.
Objective 2: Diagnosis and genetics of the TSEs in ruminant animals: Gold
standard testing of scrapie is performed by immunohistochemistry of formalin
fixed tissues, using lymphoid tissue to detect early disease and brain tissue to
detect advanced disease. Antemortem tissue based testing requires expertise in
the field and in the laboratory. We are completing a study examining the effects
of host and biopsy handling on lymphoid follicle frequency and detection of
PrP-Sc. Similarly, immunohistochemistry has been applied to determine the
effects of these factors on the frequency of observing two major cell types
known to accumulate PrPSc in lymphoid tissues—namely, macrophages and follicular
dendritic cells. These studies will be completed in FY16 and will provide
information on any needed refinements in the antemortem testing of sheep and
goats, with possible application to the evolving program of live animal testing
of captive deer and elk.
Genetic variation among animals within each species affects disease
resistance and incubation time: We have previously reported the effect of
genotype on diagnostic accuracy in white tailed deer. We have now completed a
study examining the role of a prion gene polymorphism at residue 127 in goats on
incubation time (reported in accomplishments) and in FY16 will perform studies
on diagnostic accuracy of the current testing modes in goats with this genotype.
Polymorphisms at additional sites (146 and 222) have been reported to be
associated with reduced susceptibility to caprine scrapie. Goat kids were
exposed to scrapie by the oral route on day 1 of life and are being monitored.
Goats with the potentially resistant allele have remained clinically normal for
more than 7 years after oral challenge; control goats lacking this allele
developed disease at 2-3 years of age. We will continue to monitor the 222K
goats for their natural lifespan and will perform extensive necropsy
examinations upon termination to determine whether these animals are a benefit
to the industry or represent a long lived source of prions in goat herds. The
polymorphism at residue 222, while potentially conferring resistance to scrapie,
also presents a diagnostic challenge. Residue 222 is included in the epitope
recognized by the monoclonal antibody used in gold standard diagnostic testing
in the U.S. We have reported the effect of this polymorphism on test sensitivity
(reported in accomplishments). We have previously reported that this
polymorphism is rare in U.S. goats, but in the current work, we presented some
alternatives to testing should this genotype be selected by breeders in the
future.
Examination of the prion distribution in fixed tissues is the basis for
diagnostic testing. In addition, the distribution and intensity of the
immunohistochemical staining are also useful indirect measures of disease
progression. We have reported this effect in our studies of genetics and
diagnosis of chronic wasting disease in white tailed deer. We have now extended
those studies to include Rocky Mountain elk, which have a unique prion
distribution pattern. We continue to work with state and federal agencies
monitoring the effects of genotype on prion disease captive and free-ranging
Rocky Mountain elk, as components of species-specific control programs.
While antemortem and postmortem tissue-based testing is sensitive and
specific, collection of tissues is inconvenient and testing is expensive.
Development of a blood based test might alleviate those problems. We are
conducting a systematic examination of prion-bearing cell types in sheep and
goats and have reported that all three major types of peripheral blood
mononuclear cells—B lymphocytes, T lymphocytes, and monocytes, can harbor prions
and are thus reasonable targets on which to base development of a diagnostic
platform for use during preclinical infection. We have recently reported that
relatively small amounts of blood contain infectious prions and continue to
examine methods for more sensitive and specific detection of PrP-Sc in
circulating cells.
Objective 3: Introduction of disease by novel routes: While direct contact
with prion-bearing tissues remains the most likely source of infection in sheep
and goats, the introduction of disease through fomites or through contact with
other species has not been ruled out. We originally intended to examine the role
of soil or premise contamination with prions after removal of infected sheep.
However, the success of the eradication program at reducing scrapie prevalence
to nearly undetectable levels over a relatively short amount of time suggests
that environmental routes are not highly efficient. ***However, prevalence of
chronic wasting disease in farmed and free-ranging cervids continues to climb
and as the disease is discovered in an increasing number of states and
provinces, the threat of transmission to sheep remains under investigation. In
conjunction with the Canadian Food Inspection Agency, we are completing a study
delineating methods for discriminating between a TSE of ovine and cervid origin
in sheep, using both conventional in vitro prion characterization methods and in
vivo studies with a panel of transgenic mice. The study will be concluded in
FY16; preliminary findings show differences in incubation time and molecular
folding patterns that may be useful in determining the origin of TSEs of sheep
in the CWD endemic zones.
In a continued effort to reduce research dependence on bioassay, work
continued on the creation of cultured cell lines with robust permissiveness to
natural isolates of prions. Work continued on the immortalization of caprine
microglia cell lines with different prion genotypes of interest. Studies also
continued in the optimization of the scrapie permissiveness of a caprine prion
protein-transfected rabbit kidney epithelial cell line. Factors associated with
cellular permissiveness to infection were also determined in a study that
compared the transcriptomes of clones from an immortalized ovine microglia cell
line but that differ greatly in permissiveness to natural source isolates (i.e.,
hindbrain) of classical scrapie prions.
4.Accomplishments 1. The placenta of goats with scrapie is infectious to
goat kids and lambs. The placenta of sheep is a highly infectious source of
scrapie prions and is well known to play a major role in natural transmission.
Goats, too, are a natural host of classical scrapie and are frequently raised
with sheep, but the potential routes of natural transmission from goats to sheep
have not been studied. ARS researchers at the Animal Disease Research Unit in
Pullman, Washington, have now demonstrated that the placenta shed from a goat,
despite its relatively sparse accumulation of the disease-associated form of the
prion protein, is infectious to newborn lambs and goat kids by oral exposure.
This accomplishment provides a scientific basis for regulatory and veterinary
consideration as to the possible modes of transmission risk of scrapie from
goats to sheep.
2. Prions were detected in small volume blood samples obtained from sheep
with preclinical scrapie. Initial studies that demonstrated the potential for
developing a blood-based live animal diagnostic test for classical scrapie in
sheep were based on blood sample volumes many times more than routinely used in
the practice of veterinary medicine. ARS researchers at the Animal Disease
Research Unit in Pullman, Washington, have now demonstrated that infectious
prions can be detected from much smaller blood sample volumes, even during
preclinical infection. This study supports further development of a safe and
highly efficient blood-based diagnostic test for preclinical scrapie infection
in sheep. It demonstrates the utility of using the small blood sample volumes
already routinely collected for diagnostic purposes.
3. A prion gene polymorphism that prolongs scrapie incubation in goats.
Scrapie eradication in sheep is based in part on strong genetic resistance to
classical scrapie infection. However, knowledge regarding the implications of
differing genotypes in goats is incomplete. ARS researchers at the Animal
Disease Research Unit in Pullman, Washington, have now demonstrated that the
appearance of clinical signs associated with scrapie can be significantly
delayed in goats with a prion gene polymorphism at codon 127. This
accomplishment helps explain why goats with this polymorphism may be
underrepresented in surveys of scrapie infected goat herds. Additionally, this
accomplishment suggests that scrapie eradication programs might need to include
longer trace-back histories when investigating scrapie-exposed goats of this
genotype.
4. A prion gene polymorphism that reduces the sensitivity of some
diagnostic tests for caprine scrapie. Gold standard diagnostic testing for
caprine scrapie is performed by monoclonal antibody immunohistochemistry. While
this assay is highly specific, the sensitivity of the assay is limited by the
use of a single monoclonal antibody directed to a variable portion of the prion
molecule. ARS researchers at the Animal Disease Research Unit in Pullman,
Washington, have confirmed that the monoclonal antibody currently used for
testing in the U.S. fails to detect prions in goats homozygous for a prion
polymorphism at codon 222. The study was performed by developing a digital image
segmentation and analysis algorithm to objectively measure spatially diverse
PrPSc accumulation profiles in the hindbrain of goats with naturally acquired
classical scrapie. Comparisons were also made under the standardized conditions
and reagents currently utilized by regulatory agencies. This accomplishment
provides the scientific basis for modification of the assay should this prion
genotype become more prevalent in the U.S. goat herd.
***5. Delineation of the progression of abnormal prion accumulation in the
brain of elk with chronic wasting disease. Diagnostic testing for the
transmissible spongiform encephalophathies (TSE) of elk is performed by
examination of a single section of brain, using a monoclonal antibody that
detects the abnormal prion protein. Collaborative research including scientists
from the Colorado State University Diagnostic Laboratory, the U.S. Department of
Agriculture Animal Health Inspection Service, the Canadian Food Inspection
Agency, and the ARS Animal Disease Research Unit in Pullman, Washington, has
demonstrated that the abnormal prion in this section of brain has a unique and
relatively consistent pattern of accumulation as disease progresses. The study
complements the earlier work performed by ARS and others on the effect of prion
genotype on disease progression in elk and in white tailed deer. The scoring
system described in these studies may be useful for estimating prion
distribution throughout the infected animal and potentially for estimating the
duration of infection, facilitating epidemiologic studies in infected herds.
Review Publications Schneider, D.A., Madsen-Bouterse, S.A., Zhuang, D.,
Truscott, T.C., Dassanayake, R.P., O'Rourke, K.I. 2015. The placenta shed from
goats with classical scrapie is infectious to goat kids and lambs. Journal of
General Virology. doi: 10.1099/vir.0.000151.
Munoz-Gutierrez, J.F., Schneider, D.A., Baszler, T.V., Dinkel, K.D.,
Greenlee, J.J., Nicholson, E.M., Stanton, J.J. 2015. hTERT-immortalized ovine
microglia propagate natural scrapie isolates. Virus Research. 198:35-43.
Dassanayake, R.P., White, S.N., Madsen-Bouterse, S.A., Schneider, D.A.,
O'Rourke, K.I. 2015. Role of PRNP S127 allele in experimental goat infection
with classical caprine scrapie. Animal Genetics. doi: 10.1111/age.12291.
Dassanayake, R.P., Truscott, T.C., Zhuang, D., Schneider, D.A.,
Madsen-Bouterse, S.A., Young, A.J., Stanton, J.B., Davis, W.C., O’Rourke, K.I.
2015. Classical natural ovine scrapie prions are detected in practical volumes
of blood by lamb and transgenic mouse bioassay. Journal of Veterinary Science.
16(2):179-186.
Madsen-Bouterse, S.A., Schneider, D.A., Dassanayake, R.P., Truscott, T.C.,
Zhuang, D., Kumpula-Mcwhirter, N., O'Rourke, K.I. 2015. PRNP variants in goats
reduce sensitivity of detection of PrPSc by immunoassay. Journal of Veterinary
Diagnostic Investigation. 27(3):332-343.
Spraker, T.R., Gidlewski, T., Powers, J.G., Nichols, T., Balachandran, .A.,
Cummins, B., Wild, M.A., Vercauteren, K., O'Rourke, K. 2015. Progressive
accumulation of the abnormal conformer of the prion protein and spongiform
encephalopathy in the obex of nonsymptomatic and symptomatic Rocky Mountain elk
(Cervus elaphus nelsoni) with chronic wasting disease. Journal of Veterinary
Diagnostic Investigation. doi: 10.117/1040638715593368.
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Title: Antemortem detection of chronic wasting disease prions in nasal
brush collections and rectal biopsies from white-tailed deer by real time
quaking-induced conversion
Authors
item Haley, Nicholas - item Siepker, Chris - item Walter, W. David - item
Thomsen, Bruce - item Greenlee, Justin item Lehmkuhl, Aaron - item Richt, Jürgen
-
Submitted to: Journal of Clinical Microbiology Publication Type: Peer
Reviewed Journal Publication Acceptance Date: November 27, 2015 Publication
Date: N/A
Interpretive Summary: Chronic Wasting Disease (CWD), a fatal
neurodegenerative disease that occurs in farmed and wild cervids (deer and elk)
of North America, is a transmissible spongiform encephalopathy (TSE). TSEs are
caused by infectious proteins called prions that are resistant to various
methods of decontamination and environmental degradation. Early diagnosis of CWD
in wild and captive herds would be very helpful to controlling the spread of
CWD, for which there are not yet any preventative or treatment measures
available. The purpose of this study was to test a laboratory method of prion
detection (real-time Quaking Induced Conversion; RT-QuIC) that has the potential
to detect very low levels of infectious prions in samples collected from live
animals against the gold standard diagnostic where abnormal prion in tissues is
stained on a microscope slide. This study reports that RT-QuIC detects more
cases of CWD than standard methods, but also can identify a small number of
animals without CWD as being positive. In the case of CWD, where it is likely
that large numbers of animals within a herd may be positive, misidentifying a
negative as a positive may have less of an impact than in the case of other
prion diseases such as bovine spongiform encephalopathy considering that this
test allows testing much larger numbers of samples with a faster turn around
time than traditional methods. This information could have an impact on
regulatory and wildlife officials developing plans to reduce or eliminate CWD
and cervid farmers that want to ensure that their herd remains CWD-free.
Technical Abstract: Chronic wasting disease (CWD), a transmissible
spongiform encephalopathy of cervids, was first documented nearly fifty years
ago in Colorado and Wyoming and has since spread to cervids in 23 states, 2
Canadian provinces, and the Republic of Korea. The increasing expansion of this
disease makes the development of sensitive diagnostic assays and antemortem
sampling techniques crucial for the mitigation of spread; this is especially
true in cases of relocation/reintroduction of farmed or free-ranging deer and
elk, or surveillance studies in private or protected herds where depopulation
may be contraindicated. This study sought to evaluate the sensitivity of the
real-time quaking-induced conversion (RT-QuIC) assay in samples collected
antemortem. Antemortem findings were then compared to results from ante- and
postmortem samples evaluated using the current gold standard diagnostic assay,
immunohistochemistry (IHC). Recto-anal mucosal associated lymphoid tissue
(RAMALT) biopsies and nasal brush collections from three separate herds of
farmed white-tailed deer (n=409) were evaluated, along with standard postmortem
microscopic analysis of brainstem at the level of the obex and retropharyngeal
lymph nodes. We hypothesized the sensitivity of RT-QuIC would be comparable to
IHC in antemortem tissues, and would correlate with both genotype and stage of
clinical disease. ***Our results showed that RAMALT testing by RT-QuIC had the
highest sensitivity (69.8%) when compared to postmortem testing. This data
suggests that RT-QuIC, like IHC, is a fairly sensitive assay for detection of
CWD prions in rectal biopsies and other antemortem samples, and with further
investigation has potential for large scale and rapid automated testing for CWD
diagnosis.
Research Project: Transmission, Differentiation, and Pathobiology of
Transmissible Spongiform Encephalopathies
2015 Annual Report
1a.Objectives (from AD-416): 1. Investigate the pathobiology of atypical
transmissible spongiform encephalopathies (TSEs) in natural hosts. A.
Investigate the pathobiology of atypical scrapie. B. Investigate the
pathobiology of atypical bovine spongiform encephalopathy (BSE). 2. Investigate
the horizontal transmission of TSEs. A. Assess the horizontal transmission of
sheep scrapie in the absence of lambing. B. Determine routes of transmission in
chronic wasting disease (CWD) infected premises. C. Assess oral transmission of
CWD in reindeer. 3. Investigate determinants of CWD persistence. A. Determine
CWD host range using natural routes of transmission. B. Investigate the
pathobiology of CWD.
1b.Approach (from AD-416): The studies will focus on three animal
transmissible spongiform encephalopathy (TSE) agents found in the United States:
bovine spongiform encephalopathy (BSE); scrapie of sheep and goats; and chronic
wasting disease (CWD) of deer, elk, and moose. The research will address sites
of accumulation, routes of infection, environmental persistence, and ante mortem
diagnostics with an emphasis on controlled conditions and natural routes of
infection. Techniques used will include clinical exams, histopathology,
immunohistochemistry and biochemical analysis of proteins. The enhanced
knowledge gained from this work will help mitigate the potential for
unrecognized epidemic expansions of these diseases in populations of animals
that could either directly or indirectly affect food animals.
3.Progress Report: Research efforts directed toward meeting objective 1 of
our project plan include work in previous years starting with the inoculation of
animals for studies designed to address the pathobiology of atypical scrapie,
atypical bovine spongiform encephalopathy (BSE), as well as a genetic version of
BSE. Post-mortem examination of the animals inoculated with atypical scrapie has
been initiated and laboratory analysis of the tissues is ongoing. Atypical BSE
animals have developed disease and evaluation of the samples is currently
underway. Animals inoculated with a genetic version of BSE have developed
disease with a manuscript reporting these results was published (2012), and
additional laboratory comparisons of genetic BSE to atypical and classical BSE
are ongoing. In addition, we have investigated the possibility that atypical
scrapie was present earlier than previously detected in the national flock by
analyzing archived field isolates using methods that were unavailable at the
time of original diagnosis. Sample quality was sufficiently degraded that modern
methods, beyond those applied to the tissues at the time the tissues were
archived, were not suitable for evaluation. In research pertaining to objective
2, "Investigate the horizontal transmission of TSEs", we have initiated a study
to determine if cohousing non-lambing scrapie inoculated sheep is sufficient to
transmit scrapie to neonatal lambs. At this time, scrapie free ewes have lambed
in the presence of scrapie inoculated animals and the lambs are cohoused with
these inoculated animals.
4.Accomplishments 1. Changes in retinal function in cattle can be used to
identify different types of bovine spongiform encephalopathy (BSE). BSE belongs
to a group of fatal, transmissible protein misfolding diseases known as
transmissible spongiform encephalopathies (TSEs). Like other protein misfolding
diseases including Parkinson's disease and Alzheimer's disease, TSEs are
generally not diagnosed until the onset of disease after the appearance of
unequivocal clinical signs. As such, identification of the earliest clinical
signs of disease may facilitate diagnosis. The retina is the most accessible
part of the central nervous system. ARS scientist in Ames IA described
antemortem changes in retinal function and thickness that are detectable in BSE
inoculated animals up to 11 months prior to the appearance of any other signs of
clinical disease. Differences in the severity of these clinical signs reflect
the amount of PrPSc accumulation in the retina and the resulting inflammatory
response of the tissue. These results are the earliest reported clinical signs
associated with TSE infection and provide a basis for understanding the
pathology and evaluating therapeutic interventions. Further, this work shows
that High-type BSE and classical BSE can be differentiated by eye examination
alone, the first time BSE strains have been differentiable in a live animal.
2. Sheep genetics influences the susceptibility of sheep to scrapie. Sheep
scrapie is a transmissible spongiform encephalopathy that can be transmitted
between affected animals resulting in significant economic losses in affected
flocks. The prion protein gene (PRNP) profoundly influences the susceptibility
of sheep to the scrapie agent and the tissue levels and distribution of PrPSc in
affected sheep. In this study, sheep of 3 different prion genetic types (denoted
VRQ/VRQ, VRQ/ARR and ARQ/ARR) were inoculated and subsequently euthanized upon
onset of disease. Disease aspects were uniform across genotypes and consistent
with manifestations of classical scrapie. Mean survival time differences were
associated with the genetic type such that VRQ/VRQ sheep survived 18 months,
whereas VRQ/ARR and ARQ/ARR sheep survived 60 and 56 months, respectively.
Microscopic evaluation revealed similar accumulations in central nervous system
tissues regardless of host genetic type. PrPSc in lymphoid tissue was
consistently abundant in VRQ/VRQ, present but confined to tonsil or
retropharyngeal lymph node in 4/5 VRQ/ARR, and totally absent in ARQ/ARR sheep.
The results of this study demonstrate the susceptibility of sheep with the
ARQ/ARR genotype to scrapie by the intracranial inoculation route with PrPSc
accumulation in CNS tissues, but prolonged incubation times and lack of PrPSc in
lymphoid tissue. These results are important for science based policy with
regard to testing of sheep for scrapie where some live animal testing is
conducted using lymphoid tissues which would not detect scrapie in some specific
genetic types which could limit the national scrapie eradication program.
Review Publications Greenlee J.J. 2014. The prion diseases of animals. In:
McManus, L.M., Mitchell, R.N., editors. Pathobiology of Human Disease. San
Diego: Elsevier. p. 1124-1133.
Greenlee, J.J., Kunkle, R.A., Richt, J.A., Nicholson, E.M., Hamir, A.N.
2014. Lack of prion accumulation in lymphoid tissues of PRNP ARQ/ARR sheep
intracranially inoculated with the agent of scrapie. PLoS One. 9(9):e108029.
Greenlee, J.J., West Greenlee, M.,H. 2015. The transmissible spongiform
encephalopathies of livestock. ILAR Journal. 56(1):7-25.
Munoz-Gutierrez, J.F., Schneider, D.A., Baszler, T.V., Dinkel, K.D.,
Greenlee, J.J., Nicholson, E.M., Stanton, J.J. 2015. hTERT-immortalized ovine
microglia propagate natural scrapie isolates. Virus Research. 198:35-43.
Nicholson, E.M. 2015. Detection of the disease-associated form of the prion
protein in biological samples. Bioanalysis. 7(2):253-261.
West Greenlee, M.H., Smith, J.D., Platt, E.M., Juarez, J.R., Timms, L.L,
Greenlee, J.J. 2015. Changes in retinal function and morphology are early
clinical signs of disease in cattle with bovine spongiform encephalopathy. PLoS
ONE. 10(3):e0119431.
Comoy, E.E., Mikol, J., Luccantoni-Freire, S., Correia, E.,
Lescoutra-Etchegaray, N., Durand, V., Dehen, C., Andreoletti, O., Casalone, C.,
Richt, J.A., Greenlee, J.J., Baron, T., Benestad, S., Brown, P., Deslys, J.
2015. Transmission of scrapie prions to primate after an extended silent
incubation period. Scientific Reports. 5:11573.
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Title: Transmission of scrapie prions to primate after an extended silent
incubation period
Authors
item Comoy, Emmanuel - item Mikol, Jacqueline - item Luccantoni-Freire,
Sophie - item Correia, Evelyne - item Lescoutra-Etchegaray, Nathalie - item
Durand, Valérie - item Dehen, Capucine - item Andreoletti, Olivier - item
Casalone, Cristina - item Richt, Juergen item Greenlee, Justin item Baron,
Thierry - item Benestad, Sylvie - item Hills, Bob - item Brown, Paul - item
Deslys, Jean-Philippe -
Submitted to: Scientific Reports Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 28, 2015 Publication Date: June 30, 2015
Citation: Comoy, E.E., Mikol, J., Luccantoni-Freire, S., Correia, E.,
Lescoutra-Etchegaray, N., Durand, V., Dehen, C., Andreoletti, O., Casalone, C.,
Richt, J.A., Greenlee, J.J., Baron, T., Benestad, S., Brown, P., Deslys, J.
2015. Transmission of scrapie prions to primate after an extended silent
incubation period. Scientific Reports. 5:11573.
Interpretive Summary: The transmissible spongiform encephalopathies (also
called prion diseases) are fatal neurodegenerative diseases that affect animals
and humans. The agent of prion diseases is a misfolded form of the prion protein
that is resistant to breakdown by the host cells. Since all mammals express
prion protein on the surface of various cells such as neurons, all mammals are,
in theory, capable of replicating prion diseases. One example of a prion
disease, bovine spongiform encephalopathy (BSE; also called mad cow disease),
has been shown to infect cattle, sheep, exotic undulates, cats, non-human
primates, and humans when the new host is exposed to feeds or foods contaminated
with the disease agent. The purpose of this study was to test whether non-human
primates (cynomologous macaque) are susceptible to the agent of sheep scrapie.
After an incubation period of approximately 10 years a macaque developed
progressive clinical signs suggestive of neurologic disease. Upon postmortem
examination and microscopic examination of tissues, there was a widespread
distribution of lesions consistent with a transmissible spongiform
encephalopathy. 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. Technical Abstract:
Classical bovine spongiform encephalopathy (c-BSE) is an animal prion disease
that also causes variant Creutzfeldt-Jakob disease in humans. Over the past
decades, c-BSE's zoonotic potential has been the driving force in establishing
extensive protective measures for animal and human health.
*** In complement to the recent demonstration that humanized mice are
susceptible to scrapie, we report here the first observation of direct
transmission of a natural classical scrapie isolate to a macaque after a 10-year
incubation period. Neuropathologic examination revealed all of the features of a
prion disease: spongiform change, neuronal loss, and accumulation of PrPres
throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of
scrapie to humans, at a time when protective measures for human and animal
health are being dismantled and reduced as c-BSE is considered controlled and
being eradicated.
*** Our results underscore the importance of precautionary and protective
measures and the necessity for long-term experimental transmission studies to
assess the zoonotic potential of other animal prion strains.
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Title: Scrapie transmits to white-tailed deer by the oral route and has a
molecular profile similar to chronic wasting disease
Authors
item Greenlee, Justin item Moore, S - item Smith, Jodi - item Kunkle,
Robert item West Greenlee, M -
Submitted to: American College of Veterinary Pathologists Meeting
Publication Type: Abstract Only Publication Acceptance Date: August 12, 2015
Publication Date: N/A
Technical Abstract: The purpose of this work was to determine
susceptibility of white-tailed deer (WTD) to the agent of sheep scrapie and to
compare the resultant PrPSc to that of the original inoculum and chronic wasting
disease (CWD). We inoculated WTD by a natural route of exposure (concurrent oral
and intranasal (IN); n=5) with a US scrapie isolate. All scrapie-inoculated deer
had evidence of PrPSc accumulation. PrPSc was detected in lymphoid tissues at
preclinical time points, and deer necropsied after 28 months post-inoculation
had clinical signs, spongiform encephalopathy, and widespread distribution of
PrPSc in neural and lymphoid tissues. Western blotting (WB) revealed PrPSc with
2 distinct molecular profiles. WB on cerebral cortex had a profile similar to
the original scrapie inoculum, whereas WB of brainstem, cerebellum, or lymph
nodes revealed PrPSc with a higher profile resembling CWD. Homogenates with the
2 distinct profiles from WTD with clinical scrapie were further passaged to mice
expressing cervid prion protein and intranasally to sheep and WTD. In cervidized
mice, the two inocula have distinct incubation times. Sheep inoculated
intranasally with WTD derived scrapie developed disease, but only after
inoculation with the inoculum that had a scrapie-like profile. The WTD study is
ongoing, but deer in both inoculation groups are positive for PrPSc by rectal
mucosal biopsy. In summary, this work demonstrates that WTD are susceptible to
the agent of scrapie, two distinct molecular profiles of PrPSc are present in
the tissues of affected deer, and inoculum of either profile readily passes to
deer. http://www.ars.usda.gov/research/publications/publications.htm?seq_no_115=317901
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Title: Transmission of chronic wasting disease to sentinel reindeer
(Rangifer tarandus tarandus)
Authors
item Moore, S - item Kunkle, Robert item Nicholson, Eric item Richt,
Juergen item Hamir, Amirali item Waters, Wade item Greenlee, Justin
Submitted to: American College of Veterinary Pathologists Meeting
Publication Type: Abstract Only Publication Acceptance Date: August 12, 2015
Publication Date: N/A
Technical Abstract: Chronic wasting disease (CWD) is a naturally-occurring,
fatal neurodegenerative disease of North American cervids. Reindeer (Rangifer
tarandus tarandus) are susceptible to CWD following oral challenge, but CWD has
not been reported in free-ranging caribou (Rangifer tarandus caribou) or farmed
reindeer. Potential contact between CWD-affected cervids and Rangifer species
that are free-ranging or co-housed on farms presents a potential risk of CWD
transmission. The aims of this study were to 1) investigate the transmission of
CWD from white-tailed deer (Odocoileus virginianus; CWD-wtd), mule deer
(Odocoileus hemionus; CWD-md), or elk (Cervus elaphus nelsoni; CWD-elk) to
reindeer via the intracranial route, and 2) to assess for direct and indirect
horizontal transmission to non-inoculated sentinels. Three groups of 5 reindeer
fawns were challenged intracranially with CWD-wtd, CWD-md, or CWD-elk. Two years
after challenge of inoculated reindeer, non-inoculated control reindeer were
introduced into the same pen as the CWD-wtd inoculated reindeer (n=4) or into a
pen adjacent to the CWD-md inoculated reindeer (n=2). Reindeer were allowed to
develop clinical disease. At death/euthanasia a complete necropsy examination
was performed, including immunohistochemical testing of tissues for
disease-associated CWD prion protein (PrP-CWD). Intracranially challenged
reindeer developed clinical disease from 21 months post-inoculation (MPI).
PrP-CWD was detected in 5/6 sentinel reindeer although only 2/6 developed
clinical disease during the study period (<57 and="" are="" both="" can="" cervid="" cwd="" directly="" div="" from="" have="" indirectly.="" mpi="" naive="" reindeer="" shown="" sources="" susceptible="" that="" to="" transmit="" various="" we="">
Antemortem detection of chronic wasting disease prions in nasal brush
collections and rectal biopsies from white-tailed deer by real time
quaking-induced conversion - (Peer Reviewed Journal) (27-Nov-15) Scrapie
transmits to white-tailed deer by the oral route and has a molecular profile
similar to chronic wasting disease - (Abstract Only) (12-Aug-15) Transmission of
chronic wasting disease to sentinel reindeer (Rangifer tarandus tarandus) -
(Abstract Only) (12-Aug-15) Transmission of scrapie prions to primate after an
extended silent incubation period - (Peer Reviewed Journal) Comoy, E.E., Mikol,
J., Luccantoni-Freire, S., Correia, E., Lescoutra-Etchegaray, N., Durand, V.,
Dehen, C., Andreoletti, O., Casalone, C., Richt, J.A., Greenlee, J.J., Baron,
T., Benestad, S., Brown, P., Deslys, J. 2015. Transmission of scrapie prions to
primate after an extended silent incubation period. Scientific Reports. 5:11573.
H-type bovine spongiform encephalopathy associated with E211K prion protein
polymorphism: clinical and pathologic features in wild-type and E211K cattle
following intracranial inoculation - (Abstract Only) Moore, S.J., West Greenlee,
M.H., Smith, J., Nicholson, E., Vrentas, C., Greenlee, J. 2015. H-type bovine
spongiform encephalopathy associated with E211K prion protein polymorphism:
clinical and pathologic features in wild-type and E211K cattle following
intracranial inoculation. Prion 2015. p. S5. Transmission of the agent of sheep
scrapie to deer results in PrPSc with two distinct molecular profiles -
(Abstract Only) Greenlee, J., Moore, S.J., Smith, J.., West Greenlee, M.H.,
Kunkle, R. 2015. Scrapie transmits to white-tailed deer by the oral route and
has a molecular profile similar to chronic wasting disease and distinct from the
scrapie inoculum. Prion 2015. p. S62. Development and characterization of an
ex-vivo brain slice culture model of chronic wasting disease - (Abstract Only)
Kondru, N., Greenlee, J., Greenlee, H., Manne, S., Kong, Q., Halbur, P.,
Kanthasamy, A., Kanthasamy, A. 2015. Development and characterization of an
ex-vivo brain slice culture model of chronic wasting disease. Prion 2015. p.
S68. Relationship of PrPSc molecular properties with incubation time in a
natural prion disease host: a characterization of three isolates of U.S. sheep
scrapie - (Abstract Only) Vrentas, C., Smith, J., Greenlee, J., Nicholson, E.
2015. Relationship of PrPSc molecular properties with incubation time in a
natural prion disease host: a characterization of 3 isolates of US sheep
scrapie. Prion 2015. p. S92. Clinical stage of infection is critical in the
antemortem diagnosis of chronic wasting disease in deer and elk - (Abstract
Only) (05-Mar-15) Prion peripheralization is a host-driven trait of prion
infection, independent of strain - (Abstract Only) (05-Mar-15) The transmissible
spongiform encephalopathies of livestock - (Review Article) Greenlee, J.J., West
Greenlee, M.,H. 2015. The transmissible spongiform encephalopathies of
livestock. ILAR Journal. 56(1):7-25. Raman spectroscopy reveals spectroscopic
changes in histologically normal retinas in a mouse model of
alpha-synucleinopathy - (Abstract Only) (30-Jan-15) Detection of the disease
associated form of the prion protein in biological samples - (Review Article)
Nicholson, E.M. 2015. Detection of the disease-associated form of the prion
protein in biological samples. Bioanalysis.
7(2):253-261...snip...end...tss
***NOW, for the rest of the facts, what was NOT said ;
ATYPICAL BOVINE SPONGIFORM ENCEPHALOPATHY A SPONTANEOUS EVENT OR NOT $
all one has to do is look at France. France is having one hell of an
epidemic of atypical BSE, probably why they stopped testing for BSE, problem
solved $$$ same as the USA, that’s why they stopped testing for BSE mad cow
disease in numbers they could find any with, after those atypical BSE cases
started showing up. shut down the testing to numbers set up by OIE that are so
low, you could only by accident find a case of BSE aka mad cow disease. and this
brilliant idea by the WHO et al, to change the name of mad cow disease, thinking
that might change things is preposterous. it’s all about money now folks, when
the OIE, USDA and everyone else went along and made the TSE prion disease aka
mad cow type disease a legal trading commodity by the BSE MRR policy, I would
say everyone bit off more then they can chew, and they will just have to digest
those TSE Prions coming from North America, and like it, and just prey you don’t
get a mad cow type disease i.e. Transmissible Spongiform Encephalopathy TSE
prion disease in the decades to come, and or pass it to some other poor soul via
the iatrogenic medical surgical tissue friendly fire mode of transmission i.e.
second hand transmission. it’s real folks, just not documented much, due to lack
of trace back efforts. all iatrogenic cjd is, is sporadic cjd, until the
iatrogenic event is tracked down and documented, and put into the academic and
public domain, which very seldom happens. ...
As of December 2011, around 60 atypical BSE cases have currently been
reported in 13 countries, *** with over one third in France.
***atypical spontaneous BSE in France LOL***
FRANCE STOPS TESTING FOR MAD COW DISEASE BSE, and here’s why, to many
spontaneous events of mad cow disease $$$
***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
*** 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
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
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...
P.97: Scrapie transmits to white-tailed deer by the oral route and has a
molecular profile similar to chronic wasting disease and distinct from the
scrapie inoculum
Justin Greenlee1, S Jo Moore1, Jodi Smith1, M Heather West Greenlee2, and
Robert Kunkle1 1National Animal Disease Center; Ames, IA USA; 2Iowa State
University; Ames, IA USA
The purpose of this work was to determine susceptibility of white-tailed
deer (WTD) to the agent of sheep scrapie and to compare the resultant PrPSc to
that of the original inoculum and chronic wasting disease (CWD). We inoculated
WTD by a natural route of exposure (concurrent oral and intranasal (IN); n D 5)
with a US scrapie isolate. All scrapie-inoculated deer had evidence of PrPSc
accumulation. PrPSc was detected in lymphoid tissues at preclinical time points,
and deer necropsied after 28 months post-inoculation had clinical signs,
spongiform encephalopathy, and widespread distribution of PrPSc in neural and
lymphoid tissues. Western blotting (WB) revealed PrPSc with 2 distinct molecular
profiles. WB on cerebral cortex had a profile similar to the original scrapie
inoculum, whereas WB of brainstem, cerebellum, or lymph nodes revealed PrPSc
with a higher profile resembling CWD. Homogenates with the 2 distinct profiles
from WTD with clinical scrapie were further passaged to mice expressing cervid
prion protein and intranasally to sheep and WTD. In cervidized mice, the 2
inocula have distinct incubation times. Sheep inoculated intranasally with WTD
derived scrapie developed disease, but only after inoculation with the inoculum
that had a scrapie-like profile. The WTD study is ongoing, but deer in both
inoculation groups are positive for PrPSc by rectal mucosal biopsy. In summary,
this work demonstrates that WTD are susceptible to the agent of scrapie, 2
distinct molecular profiles of PrPSc are present in the tissues of affected
deer, and inoculum of either profile readily passes to deer.
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
Tuesday, December 23, 2014
FDA PART 589 -- SUBSTANCES PROHIBITED FROM USE IN ANIMAL FOOD OR FEED
VIOLATIONS OFFICIAL ACTION INDICATED OAI UPDATE DECEMBER 2014 BSE TSE PRION
Monday, October 26, 2015
FDA PART 589 -- SUBSTANCES PROHIBITED FROM USE IN ANIMAL FOOD OR FEED
VIOLATIONS OFFICIAL ACTION INDICATED OIA UPDATE October 2015
Sunday, June 14, 2015
Larry’s Custom Meats Inc. Recalls Beef Tongue Products That May Contain
Specified Risk Materials BSE TSE Prion
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Title: Scrapie transmits to white-tailed deer by the oral route and has a
molecular profile similar to chronic wasting disease
Authors
item Greenlee, Justin item Moore, S - item Smith, Jodi - item Kunkle,
Robert item West Greenlee, M -
Submitted to: American College of Veterinary Pathologists Meeting
Publication Type: Abstract Only Publication Acceptance Date: August 12, 2015
Publication Date: N/A Technical Abstract: The purpose of this work was to
determine susceptibility of white-tailed deer (WTD) to the agent of sheep
scrapie and to compare the resultant PrPSc to that of the original inoculum and
chronic wasting disease (CWD). We inoculated WTD by a natural route of exposure
(concurrent oral and intranasal (IN); n=5) with a US scrapie isolate. All
scrapie-inoculated deer had evidence of PrPSc accumulation. PrPSc was detected
in lymphoid tissues at preclinical time points, and deer necropsied after 28
months post-inoculation had clinical signs, spongiform encephalopathy, and
widespread distribution of PrPSc in neural and lymphoid tissues. Western
blotting (WB) revealed PrPSc with 2 distinct molecular profiles. WB on cerebral
cortex had a profile similar to the original scrapie inoculum, whereas WB of
brainstem, cerebellum, or lymph nodes revealed PrPSc with a higher profile
resembling CWD. Homogenates with the 2 distinct profiles from WTD with clinical
scrapie were further passaged to mice expressing cervid prion protein and
intranasally to sheep and WTD. In cervidized mice, the two inocula have distinct
incubation times. Sheep inoculated intranasally with WTD derived scrapie
developed disease, but only after inoculation with the inoculum that had a
scrapie-like profile. The WTD study is ongoing, but deer in both inoculation
groups are positive for PrPSc by rectal mucosal biopsy. In summary, this work
demonstrates that WTD are susceptible to the agent of scrapie, two distinct
molecular profiles of PrPSc are present in the tissues of affected deer, and
inoculum of either profile readily passes to deer.
White-tailed Deer are Susceptible to Scrapie by Natural Route of Infection
Jodi D. Smith, Justin J. Greenlee, and Robert A. Kunkle; Virus and Prion
Research Unit, National Animal Disease Center, USDA-ARS
Interspecies transmission studies afford the opportunity to better
understand the potential host range and origins of prion diseases. Previous
experiments demonstrated that white-tailed deer are susceptible to sheep-derived
scrapie by intracranial inoculation. The purpose of this study was to determine
susceptibility of white-tailed deer to scrapie after a natural route of
exposure. Deer (n=5) were inoculated by concurrent oral (30 ml) and intranasal
(1 ml) instillation of a 10% (wt/vol) brain homogenate derived from a sheep
clinically affected with scrapie. Non-inoculated deer were maintained as
negative controls. All deer were observed daily for clinical signs. Deer were
euthanized and necropsied when neurologic disease was evident, and tissues were
examined for abnormal prion protein (PrPSc) by immunohistochemistry (IHC) and
western blot (WB). One animal was euthanized 15 months post-inoculation (MPI)
due to an injury. At that time, examination of obex and lymphoid tissues by IHC
was positive, but WB of obex and colliculus were negative. Remaining deer
developed clinical signs of wasting and mental depression and were necropsied
from 28 to 33 MPI. Tissues from these deer were positive for scrapie by IHC and
WB. Tissues with PrPSc immunoreactivity included brain, tonsil, retropharyngeal
and mesenteric lymph nodes, hemal node, Peyer’s patches, and spleen. This work
demonstrates for the first time that white-tailed deer are susceptible to sheep
scrapie by potential natural routes of inoculation. In-depth analysis of tissues
will be done to determine similarities between scrapie in deer after
intracranial and oral/intranasal inoculation and chronic wasting disease
resulting from similar routes of inoculation.
see full text ;
PO-039: A comparison of scrapie and chronic wasting disease in white-tailed
deer
Justin Greenlee, Jodi Smith, Eric Nicholson US Dept. Agriculture;
Agricultural Research Service, National Animal Disease Center; Ames, IA USA
White-tailed deer are susceptible to the agent of sheep scrapie by
intracerebral inoculation
snip...
It is unlikely that CWD will be eradicated from free-ranging cervids, and
the disease is likely to continue to spread geographically [10]. However, the
potential that white-tailed deer may be susceptible to sheep scrapie by a
natural route presents an additional confounding factor to halting the spread of
CWD. This leads to the additional speculations that
1) infected deer could serve as a reservoir to infect sheep with scrapie
offering challenges to scrapie eradication efforts and
2) CWD spread need not remain geographically confined to current endemic
areas, but could occur anywhere that sheep with scrapie and susceptible cervids
cohabitate.
This work demonstrates for the first time that white-tailed deer are
susceptible to sheep scrapie by intracerebral inoculation with a high attack
rate and that the disease that results has similarities to CWD. These
experiments will be repeated with a more natural route of inoculation to
determine the likelihood of the potential transmission of sheep scrapie to
white-tailed deer. If scrapie were to occur in white-tailed deer, results of
this study indicate that it would be detected as a TSE, but may be difficult to
differentiate from CWD without in-depth biochemical analysis.
2012
PO-039: A comparison of scrapie and chronic wasting disease in white-tailed
deer
Justin Greenlee, Jodi Smith, Eric Nicholson US Dept. Agriculture;
Agricultural Research Service, National Animal Disease Center; Ames, IA USA
snip...
The results of this study suggest that there are many similarities in the
manifestation of CWD and scrapie in WTD after IC inoculation including early and
widespread presence of PrPSc in lymphoid tissues, clinical signs of depression
and weight loss progressing to wasting, and an incubation time of 21-23 months.
Moreover, western blots (WB) done on brain material from the obex region have a
molecular profile similar to CWD and distinct from tissues of the cerebrum or
the scrapie inoculum. However, results of microscopic and IHC examination
indicate that there are differences between the lesions expected in CWD and
those that occur in deer with scrapie: amyloid plaques were not noted in any
sections of brain examined from these deer and the pattern of immunoreactivity
by IHC was diffuse rather than plaque-like.
*** After a natural route of exposure, 100% of WTD were susceptible to
scrapie.
Deer developed clinical signs of wasting and mental depression and were
necropsied from 28 to 33 months PI. Tissues from these deer were positive for
PrPSc by IHC and WB. Similar to IC inoculated deer, samples from these deer
exhibited two different molecular profiles: samples from obex resembled CWD
whereas those from cerebrum were similar to the original scrapie inoculum. On
further examination by WB using a panel of antibodies, the tissues from deer
with scrapie exhibit properties differing from tissues either from sheep with
scrapie or WTD with CWD. Samples from WTD with CWD or sheep with scrapie are
strongly immunoreactive when probed with mAb P4, however, samples from WTD with
scrapie are only weakly immunoreactive. In contrast, when probed with mAb’s 6H4
or SAF 84, samples from sheep with scrapie and WTD with CWD are weakly
immunoreactive and samples from WTD with scrapie are strongly positive. This
work demonstrates that WTD are highly susceptible to sheep scrapie, but on first
passage, scrapie in WTD is differentiable from CWD.
2011
*** After a natural route of exposure, 100% of white-tailed deer were
susceptible to scrapie.
White-tailed Deer are Susceptible to Scrapie by Natural Route of Infection
Jodi D. Smith, Justin J. Greenlee, and Robert A. Kunkle; Virus and Prion
Research Unit, National Animal Disease Center, USDA-ARS
Interspecies transmission studies afford the opportunity to better
understand the potential host range and origins of prion diseases. Previous
experiments demonstrated that white-tailed deer are susceptible to sheep-derived
scrapie by intracranial inoculation. The purpose of this study was to determine
susceptibility of white-tailed deer to scrapie after a natural route of
exposure. Deer (n=5) were inoculated by concurrent oral (30 ml) and intranasal
(1 ml) instillation of a 10% (wt/vol) brain homogenate derived from a sheep
clinically affected with scrapie. Non-inoculated deer were maintained as
negative controls. All deer were observed daily for clinical signs. Deer were
euthanized and necropsied when neurologic disease was evident, and tissues were
examined for abnormal prion protein (PrPSc) by immunohistochemistry (IHC) and
western blot (WB). One animal was euthanized 15 months post-inoculation (MPI)
due to an injury. At that time, examination of obex and lymphoid tissues by IHC
was positive, but WB of obex and colliculus were negative. Remaining deer
developed clinical signs of wasting and mental depression and were necropsied
from 28 to 33 MPI. Tissues from these deer were positive for scrapie by IHC and
WB. Tissues with PrPSc immunoreactivity included brain, tonsil, retropharyngeal
and mesenteric lymph nodes, hemal node, Peyer’s patches, and spleen. This work
demonstrates for the first time that white-tailed deer are susceptible to sheep
scrapie by potential natural routes of inoculation. In-depth analysis of tissues
will be done to determine similarities between scrapie in deer after
intracranial and oral/intranasal inoculation and chronic wasting disease
resulting from similar routes of inoculation.
see full text ;
***********OCTOBER 2015*************
*** PRION 2015 ORAL AND POSTER CONGRESSIONAL ABSTRACTS ***
THANK YOU PRION 2015 TAYLOR & FRANCIS, Professor Chernoff, and
Professor Aguzzi et al, for making these PRION 2015 Congressional Poster and
Oral Abstracts available freely to the public. ...Terry S. Singeltary Sr.
P.108: Successful oral challenge of adult cattle with classical BSE
Sandor Dudas1,*, Kristina Santiago-Mateo1, Tammy Pickles1, Catherine
Graham2, and Stefanie Czub1 1Canadian Food Inspection Agency; NCAD Lethbridge;
Lethbridge, Alberta, Canada; 2Nova Scotia Department of Agriculture; Pathology
Laboratory; Truro, Nova Scotia, Canada
Classical Bovine spongiform encephalopathy (C-type BSE) is a feed- and
food-borne fatal neurological disease which can be orally transmitted to cattle
and humans. Due to the presence of contaminated milk replacer, it is generally
assumed that cattle become infected early in life as calves and then succumb to
disease as adults. Here we challenged three 14 months old cattle per-orally with
100 grams of C-type BSE brain to investigate age-related susceptibility or
resistance. During incubation, the animals were sampled monthly for blood and
feces and subjected to standardized testing to identify changes related to
neurological disease. At 53 months post exposure, progressive signs of central
nervous system disease were observed in these 3 animals, and they were
euthanized. Two of the C-BSE animals tested strongly positive using standard BSE
rapid tests, 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. Our study demonstrates susceptibility of adult
cattle to oral transmission of classical BSE. We are further examining
explanations for the unusual disease presentation in the third challenged
animal.
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, Val erie 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 longe 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.
================
==========================================
***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.
==========================================
It also appears to Mr MacLean that Mr Bradley’s answer (that it would take
less than say 100 grams) was probably given with the benefit of hindsight:
particularly if one considers that later in the same answer Mr Bradley expresses
his surprise that it could take as little of 1 gram of brain to cause BSE by the
oral route within the same species. This information did not become available
until the “attack rate” experiment had been completed in 1995/96. This was a
titration experiment designed to ascertain the infective
2
dose. A range of dosages was used to ensure that the actual result was
within both a lower and an upper limit within the study and the designing
scientists would not have expected all the dose levels to trigger infection. The
dose ranges chosen by the most informed scientists at that time ranged from 1
gram to three times one hundred grams. It is clear that the designing scientists
must also have shared Mr Bradley’s surprise at the results because all the dose
levels right down to 1 gram triggered infection.
It is clear that the designing scientists must also have shared Mr Bradleys
surprise at the results because all the dose levels right down to 1 gram
triggered infection.
it is clear that the designing scientists must have also shared Mr Bradleys
surprise at the results because all the dose levels right down to 1 gram
triggered infection.
Evidence That Transmissible Mink Encephalopathy Results from Feeding
Infected Cattle
Over the next 8-10 weeks, approximately 40% of all the adult mink on the
farm died from TME.
snip...
The rancher was a ''dead stock'' feeder using mostly (>95%) downer or
dead dairy cattle...
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. ...
*** 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.***
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
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.***
HD.13: CWD infection in the spleen of humanized transgenic mice
Liuting Qing and Qingzhong Kong Case Western Reserve University; Cleveland,
OH USA
Chronic wasting disease (CWD) is a widespread prion disease in free-ranging
and captive cervid species in North America, and there is evidence suggesting
the existence of multiple CWD strains. The susceptibility of human CNS and
peripheral organs to the various CWD prion strains remains largely unclear.
Current literature suggests that the classical CWD strain is unlikely to infect
human brain, but the potential for peripheral infection by CWD in humans is
unknown. We detected protease-resistant PrPSc in the spleens of a few humanized
transgenic mice that were intracerebrally inoculated with natural CWD isolates,
but PrPSc was not detected in the brains of any of the CWD-inoculated mice. Our
ongoing bioassays in humanized Tg mice indicate that intracerebral challenge
with such PrPSc-positive humanized mouse spleen already led to prion disease in
most animals. These results indicate that the CWD prion may have the potential
to infect human peripheral lymphoid tissues.
From: Terry S. Singeltary Sr.
Sent: Saturday, November 15, 2014 9:29 PM
To: Terry S. Singeltary Sr.
Subject: THE EPIDEMIOLOGY OF CREUTZFELDT-JAKOB DISEASE R. G. WILL 1984
THE EPIDEMIOLOGY OF CREUTZFELDT-JAKOB DISEASE
R. G. WILL
1984
*** 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). (SEE LINK IN REPORT HERE...TSS) PLUS, THE CDC DID NOT PUT
THIS WARNING OUT FOR THE WELL BEING OF THE DEER AND ELK ;
snip...
85%+ of all human tse prion disease is sporadic CJD.
see what the NIH prion Gods say themselves ;
‘’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.’’
‘’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.’’
*** 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 ***
*** 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).***
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Title: Transmission of scrapie prions to primate after an extended silent
incubation period
Authors
item Comoy, Emmanuel - item Mikol, Jacqueline - item Luccantoni-Freire,
Sophie - item Correia, Evelyne - item Lescoutra-Etchegaray, Nathalie - item
Durand, Valérie - item Dehen, Capucine - item Andreoletti, Olivier - item
Casalone, Cristina - item Richt, Juergen item Greenlee, Justin item Baron,
Thierry - item Benestad, Sylvie - item Hills, Bob - item Brown, Paul - item
Deslys, Jean-Philippe -
Submitted to: Scientific Reports Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 28, 2015 Publication Date: June 30, 2015
Citation: Comoy, E.E., Mikol, J., Luccantoni-Freire, S., Correia, E.,
Lescoutra-Etchegaray, N., Durand, V., Dehen, C., Andreoletti, O., Casalone, C.,
Richt, J.A., Greenlee, J.J., Baron, T., Benestad, S., Brown, P., Deslys, J.
2015. Transmission of scrapie prions to primate after an extended silent
incubation period. Scientific Reports. 5:11573.
Interpretive Summary:
The transmissible spongiform encephalopathies (also called prion diseases)
are fatal neurodegenerative diseases that affect animals and humans. The agent
of prion diseases is a misfolded form of the prion protein that is resistant to
breakdown by the host cells. Since all mammals express prion protein on the
surface of various cells such as neurons, all mammals are, in theory, capable of
replicating prion diseases. One example of a prion disease, bovine spongiform
encephalopathy (BSE; also called mad cow disease), has been shown to infect
cattle, sheep, exotic undulates, cats, non-human primates, and humans when the
new host is exposed to feeds or foods contaminated with the disease agent. The
purpose of this study was to test whether non-human primates (cynomologous
macaque) are susceptible to the agent of sheep scrapie. After an incubation
period of approximately 10 years a macaque developed progressive clinical signs
suggestive of neurologic disease. Upon postmortem examination and microscopic
examination of tissues, there was a widespread distribution of lesions
consistent with a transmissible spongiform encephalopathy. 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.
Technical Abstract:
Classical bovine spongiform encephalopathy (c-BSE) is an animal prion
disease that also causes variant Creutzfeldt-Jakob disease in humans. Over the
past decades, c-BSE's zoonotic potential has been the driving force in
establishing extensive protective measures for animal and human health. In
complement to the recent demonstration that humanized mice are susceptible to
scrapie, we report here the first observation of direct transmission of a
natural classical scrapie isolate to a macaque after a 10-year incubation
period. Neuropathologic examination revealed all of the features of a prion
disease: spongiform change, neuronal loss, and accumulation of PrPres throughout
the CNS.
***This observation strengthens the questioning of the harmlessness of
scrapie to humans, at a time when protective measures for human and animal
health are being dismantled and reduced as c-BSE is considered controlled and
being eradicated. Our results underscore the importance of precautionary and
protective measures and the necessity for long-term experimental transmission
studies to assess the zoonotic potential of other animal prion strains.
*** Docket No. APHIS-2007-0127 Scrapie in Sheep and Goats Terry Singeltary
Sr. Submission ***
Docket No. APHIS-2007-0127 Scrapie in Sheep and Goats
SUMMARY: We are reopening the comment period for our proposed rule that
would revise completely the scrapie regulations, which concern the risk groups
and categories established for individual animals and for flocks, the use of
genetic testing as a means of assigning risk levels to animals, movement
restrictions for animals found to be genetically less susceptible or resistant
to scrapie, and recordkeeping requirements. This action will allow interested
persons additional time to prepare and submit comments.
DATES: The comment period for the proposed rule published on September 10,
2015 (80 FR 54660-54692) is reopened. We will consider all comments that we
receive on or before December 9, 2015. ...
COMMENT SUBMISSION TERRY S. SINGELTARY SR.
WITH regards to Docket No. APHIS-2007-0127 Scrapie in Sheep and Goats, I
kindly submit the following ;
>>>The last major revision of the scrapie regulations occurred on
August 21, 2001, when we published in theFederal Register(66 FR 43964, Docket
No. 97-093-5) a final rule amending part 79 by imposing additional restrictions
on the interstate movement of sheep and goats.<<<
Indeed, much science has changed about the Scrapie TSE prion, including
more science linking Scrapie to humans. sadly, politics, industry, and trade,
have not changed, and those usually trump sound science, as is the case with all
Transmissible Spongiform Encephalopathy TSE Prion disease in livestock producing
animals and the OIE. we can look no further at the legal trading of the Scrapie
TSE prion both typical and atypical of all strains, and CWD all stains. With as
much science of old, and now more new science to back this up, Scrapie of all
types i.e. atypical and typical, BSE all strains, and CWD all strains, should be
regulated in trade as BSE TSE PRION. In fact, I urge APHIS et al and the OIE,
and all trading partners to take heed to the latest science on the TSE prion
disease, all of them, and seriously reconsider the blatant disregards for human
and animal health, all in the name of trade, with the continued relaxing of TSE
Prion trade regulations through the ‘NEGLIGIBLE BSE RISK’ PROGRAM, which was set
up to fail in the first place. If the world does not go back to the ‘BSE RISK
ASSESSMENTS’, enhance, and or change that assessment process to include all TSE
prion disease, i.e. ‘TSE RISK ASSESSMENT’, if we do not do this and if we
continue this farce with OIE and the USDA et al, and the ‘NEGLIGIBLE BSE RISK’
PROGRAM, we will never eradicate the TSE prion aka mad cow type disease, they
will continue to mutate and spread among species of human and animal origin, and
they will continue to kill. ...
please see ;
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 longe 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***
===============
ARS VIRUS AND PRION RESEARCH / Research / Publication #277212
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Title: Susceptibility of cattle to the agent of chronic wasting disease
from elk after intracranial inoculation
Authors
item Greenlee, Justin item Nicholson, Eric item Smith, Jodi item Kunkle,
Robert item Hamir, Amirali
Submitted to: Journal of Veterinary Diagnostic Investigation Publication
Type: Peer Reviewed Journal Publication Acceptance
Date: July 12, 2012
Publication Date: November 1, 2012
Citation: Greenlee, J.J., Nicholson, E.M., Smith, J.D., Kunkle, R.A.,
Hamir, A.N. 2012.
Susceptibility of cattle to the agent of chronic wasting disease from elk
after intracranial inoculation.
Journal of Veterinary Diagnostic Investigation. 24(6):1087-1093.
Interpretive Summary: Chronic Wasting Disease (CWD), a fatal
neurodegenerative disease that occurs in farmed and wild cervids (deer and elk)
of North America, is a transmissible spongiform encephalopathy (TSE). TSEs are
caused by infectious proteins called prions that are resistant to various
methods of decontamination and environmental degradation. Cattle could be
exposed to chronic wasting disease (CWD) by contact with infected farmed or
free-ranging cervids. The purpose of this study was to assess the potential
transmission of CWD from elk to cattle after intracranial inoculation, the most
direct route to test the potential of a host to replicate an isolate of the
prion agent. This study reports that only 2 of 14 calves inoculated with CWD
from elk had clinical signs or evidence of abnormal prion protein accumulation.
These results suggest that cattle are unlikely to be susceptible to CWD if
inoculated by a more natural route. This information could have an impact on
regulatory officials developing plans to reduce or eliminate TSEs and farmers
with concerns about ranging cattle on areas where CWD may be present.
Technical Abstract:
***Cattle could be exposed to the agent of chronic wasting disease (CWD)
through contact with infected farmed or free-ranging cervids or exposure to
contaminated premises. The purpose of this study was to assess the potential for
CWD derived from elk to transmit to cattle after intracranial inoculation.
Calves (n=14) were inoculated with brain homogenate derived from elk with CWD to
determine the potential for transmission and define the clinicopathologic
features of disease.
Cattle were necropsied if clinical signs occurred or at the termination of
experiment (49 months post-inoculation (MPI)).
Clinical signs of poor appetite, weight loss, circling, and bruxism
occurred in two cattle (14%) at 16 and 17 MPI, respectively.
Accumulation of abnormal prion protein (PrP**Sc) in these cattle was
confined to the central nervous system with the most prominent immunoreactivity
in midbrain, brainstem, and hippocampus with lesser immunoreactivity in the
cervical spinal cord.
*** The rate of transmission was lower than in cattle inoculated with CWD
derived from mule deer (38%) or white-tailed deer (86%).
Additional studies are required to fully assess the potential for cattle
to develop CWD through a more natural route of exposure, but a low rate of
transmission after intracranial inoculation suggests that risk of transmission
through other routes is low.
***A critical finding here is that if CWD did transmit to exposed cattle,
currently used diagnostic techniques would detect and differentiate it from
other prion diseases in cattle based on absence of spongiform change, distinct
pattern of PrP**Sc deposition, and unique molecular profile.
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES Project Number: 5030-32000-103-00
Project Type: Appropriated
Start Date: Oct 01, 2011 End Date: Sep 30, 2016
Objective: 1. Investigate the pathobiology of atypical transmissible
spongiform encephalopathies (TSEs) in natural hosts. A. Investigate the
pathobiology of atypical scrapie. B. Investigate the pathobiology of atypical
bovine spongiform encephalopathy (BSE). 2. Investigate the horizontal
transmission of TSEs. A. Assess the horizontal transmission of sheep scrapie in
the absence of lambing. B. Determine routes of transmission in chronic wasting
disease (CWD) infected premises. C. Assess oral transmission of CWD in reindeer.
3. Investigate determinants of CWD persistence. A. Determine CWD host range
using natural routes of transmission. B. Investigate the pathobiology of CWD.
Approach: The studies will focus on three animal transmissible spongiform
encephalopathy (TSE) agents found in the United States: bovine spongiform
encephalopathy (BSE); scrapie of sheep and goats; and chronic wasting disease
(CWD) of deer, elk, and moose. The research will address sites of accumulation,
routes of infection, environmental persistence, and ante mortem diagnostics with
an emphasis on controlled conditions and natural routes of infection. Techniques
used will include clinical exams, histopathology, immunohistochemistry and
biochemical analysis of proteins. The enhanced knowledge gained from this work
will help mitigate the potential for unrecognized epidemic expansions of these
diseases in populations of animals that could either directly or indirectly
affect food animals.
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES 2014 Annual Report
1a.Objectives (from AD-416): 1. Investigate the pathobiology of atypical
transmissible spongiform encephalopathies (TSEs) in natural hosts. A.
Investigate the pathobiology of atypical scrapie. B. Investigate the
pathobiology of atypical bovine spongiform encephalopathy (BSE). 2. Investigate
the horizontal transmission of TSEs. A. Assess the horizontal transmission of
sheep scrapie in the absence of lambing. B. Determine routes of transmission in
chronic wasting disease (CWD) infected premises. C. Assess oral transmission of
CWD in reindeer. 3. Investigate determinants of CWD persistence. A. Determine
CWD host range using natural routes of transmission. B. Investigate the
pathobiology of CWD.
1b.Approach (from AD-416): The studies will focus on three animal
transmissible spongiform encephalopathy (TSE) agents found in the United States:
bovine spongiform encephalopathy (BSE); scrapie of sheep and goats; and chronic
wasting disease (CWD) of deer, elk, and moose. The research will address sites
of accumulation, routes of infection, environmental persistence, and ante mortem
diagnostics with an emphasis on controlled conditions and natural routes of
infection. Techniques used will include clinical exams, histopathology,
immunohistochemistry and biochemical analysis of proteins. The enhanced
knowledge gained from this work will help mitigate the potential for
unrecognized epidemic expansions of these diseases in populations of animals
that could either directly or indirectly affect food animals.
3.Progress Report: Research efforts directed toward meeting objective 1 of
our project plan, Investigate the pathobiology of atypical transmissible
spongiform encephalopathies (TSEs) in natural hosts, include work in previous
years starting with the inoculation of animals for studies designed to address
the pathobiology of atypical scrapie, atypical bovine spongiform encephalopathy
(BSE), as well as a genetic version of BSE. Animals inoculated with atypical
scrapie have not yet developed disease. Atypical BSE animals have developed
disease and evaluation of the samples is currently underway. Animals inoculated
with a genetic version of BSE have developed disease and the manuscript has been
published (2012). In addition, we have investigated the possibility that
atypical scrapie was present earlier than previously detected in the national
flock by analyzing archived field isolates using methods that were unavailable
at the time of original diagnosis. Sample quality was sufficiently degraded that
modern methods were not suitable for evaluation. In research pertaining to
objective 2, Investigate the horizontal transmission of TSEs, we have initiated
a study to determine if cohousing non-lambing scrapie inoculated sheep is
sufficient to transmit scrapie to neonatal lambs. At this time, scrapie free
ewes have lambed in the presence of scrapie inoculated animals and the lambs are
cohoused with these inoculated animals.
4.Accomplishments 1. Evaluated enzyme immunoassay for rapid identification
of prion disease in livestock. Scrapie of sheep and bovine spongiform
encephalopathy of cattle are diseases that cause damage to the central nervous
system including the retina in the eye. The infectious agent is an abnormal
protein called a prion that has misfolded from its normal state and is resistant
to breakdown by the host cells. Current diagnostic methods require the testing
of brain material, which can be difficult to collect and may lead to
contamination of the environment and exposure of personnel to the infectious
agent. Eyes can be readily collected without opening the skull. ARS researchers
at Ames, Iowa demonstrated that the enzyme immunoassay results using eyes of
negative controls or samples collected from sheep or cattle with clinical signs
were in agreement with approved confirmatory assays (western blot or
immunohistochemistry). These results indicate the retina is a useful tissue for
rapid diagnosis of prion disease in clinically ill sheep and cattle and could be
considered to greatly increase the number of samples submitted for prion disease
diagnosis with a minimal investment of time and limited exposure of personnel to
prion agents.
2. Evaluated E211K cattle as a model for inherited human prion disease.
Prion diseases cause damage to the central nervous system of animals and humans.
The infectious agent is an abnormal protein called a prion that has misfolded
from its normal state and is resistant to breakdown by the host cells and thus
accumulates and damages those cells. Some forms of prion disease are genetic and
can be inherited. Current models of genetic prion disease in humans rely on
mouse models expressing either the human prion protein (E200K) or a combination
of both mouse and human sequences. In addition to being an entirely artificial
system these mouse models have a short lifespan making them a less than ideal
system to study a naturally occurring genetic disorder with a long incubation
time and late onset of disease. Cattle, however, exhibit a number of
similarities to humans with regard to prion disease and perhaps most notable is
the late onset of genetic prion disease. ARS researchers at Ames, Iowa have
produced cattle containing both 1 and 2 chromosome copies of the cattle prion
gene (E211K) and evaluated many aspects of this prion protein from cattle
including protein stability, protein expression levels and ratios, as well as
evidence of oxidative stress. Taken together, these results highlight the
differences between mouse models of genetic prion disease and a naturally
occurring prion disease system in cattle and suggest that cattle will provide a
more relevant understanding of genetic prion disease in humans than do current
rodent models.
Review Publications Smith, J.D., Greenlee, J.J. 2014. Detection of
misfolded prion protein in retina samples of sheep and cattle by use of a
commercially available enzyme immunoassay. American Journal of Veterinary
Research. 75(3):268-272.
Haldar, S., Beveridge, A.J., Wong, J., Singh, A.J., Galimberti, D.,
Borroni, D., Zhu, X., Blevins, J., Greenlee, J., Perry, G., Mukhopadhyay, C.K.,
Schmotzer, C., Singh, N. 2014. A low-molecular-weight ferroxidase is increased
in the CSF of sCJD Cases: CSF ferroxidase and transferrin as diagnostic
biomarkers for sCJD. Antioxidants & Redox Signaling. 19(14):1662-1675.
*** P.126: Successful transmission of chronic wasting disease (CWD) into
mice over-expressing bovine prion protein (TgSB3985) ***
Larisa Cervenakova,1 Christina J Sigurdson,2 Pedro Piccardo,3 Oksana
Yakovleva,1 Irina Vasilyeva,1 Jorge de Castro,1 Paula Saá,1 and Anton Cervenak1
1American Red Cross, Holland Laboratory; Rockville, MD USA; 2University of
California; San Diego, CA USA; 3Lab TSE/OBRR /CBER/FDA; Rockville, MD USA
Keywords: chronic wasting disease, transmission, transgenic mouse, bovine
prion protein
Background. CWD is a disease affecting wild and farmraised cervids in
North America. Epidemiological studies provide no evidence of CWD transmission
to humans. Multiple attempts have failed to infect transgenic mice expressing
human PRNP gene with CWD. The extremely low efficiency of PrPCWD to convert
normal human PrPC in vitro provides additional evidence that transmission of CWD
to humans cannot be easily achieved. However, a concern about the risk of CWD
transmission to humans still exists. This study aimed to establish and
characterize an experimental model of CWD in TgSB3985 mice with the following
attempt of transmission to TgHu mice.
Materials and Methods. TgSB3985 mice and wild-type FVB/ NCrl mice were
intracranially injected with 1% brain homogenate from a CWD-infected Tga20 mouse
(CWD/Tga20). TgSB3985 and TgRM (over-expressing human PrP) were similarly
injected with 5% brain homogenates from CWD-infected white-tailed deer (CWD/WTD)
or elk (CWD/Elk). Animals were observed for clinical signs of neurological
disease and were euthanized when moribund. Brains and spleens were removed from
all mice for PrPCWD detection by Western blotting (WB). A histological analysis
of brains from selected animals was performed: brains were scored for the
severity of spongiform change, astrogliosis, and PrPCWD deposition in ten brain
regions.
Results. Clinical presentation was consistent with TSE. More than 90% of
TgSB3985 and wild-type mice infected with CWD/Tga20, tested positive for PrPres
in the brain but only mice in the latter group carried PrPCWD in their spleens.
We found evidence for co-existence or divergence of two CWD/ Tga20 strains based
on biochemical and histological profiles. In TgSB3985 mice infected with CWD-elk
or CWD-WTD, no animals tested positive for PrPCWD in the brain or in the spleen
by WB. However, on neuropathological examination we found presence of amyloid
plaques that stained positive for PrPCWD in three CWD/WTD- and two
CWD/Elk-infected TgSB3985 mice. The neuropathologic profiles in CWD/WTD- and
CWD/Elkinfected mice were similar but unique as compared to profiles of BSE,
BSE-H or CWD/Tg20 agents propagated in TgSB3985 mice. None of CWD-infected TgRM
mice tested positive for PrPCWD by WB or by immunohistochemical detection.
Conclusions. To our knowledge, this is the first established experimental
model of CWD in TgSB3985. We found evidence for co-existence or divergence of
two CWD strains adapted to Tga20 mice and their replication in TgSB3985 mice.
Finally, we observed phenotypic differences between cervid-derived CWD and
CWD/Tg20 strains upon propagation in TgSB3985 mice. Further studies are underway
to characterize these strains.
TSS
UPDATED CORRESPONDENCE FROM AUTHORS OF THIS STUDY I.E. COLBY, PRUSINER ET
AL, ABOUT MY CONCERNS OF THE DISCREPANCY BETWEEN THEIR FIGURES AND MY FIGURES OF
THE STUDIES ON CWD TRANSMISSION TO CATTLE ;
CWD to cattle figures CORRECTION
Greetings,
I believe the statement and quote below is incorrect ;
"CWD has been transmitted to cattle after intracerebral inoculation,
although the infection rate was low (4 of 13 animals [Hamir et al. 2001]). This
finding raised concerns that CWD prions might be transmitted to cattle grazing
in contaminated pastures."
Please see ;
Within 26 months post inoculation, 12 inoculated animals had lost weight,
revealed abnormal clinical signs, and were euthanatized. Laboratory tests
revealed the presence of a unique pattern of the disease agent in tissues of
these animals. These findings demonstrate that when CWD is directly inoculated
into the brain of cattle, 86% of inoculated cattle develop clinical signs of the
disease.
" although the infection rate was low (4 of 13 animals [Hamir et al.
2001]). "
shouldn't this be corrected, 86% is NOT a low rate. ...
kindest regards,
Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518
Thank you!
Thanks so much for your updates/comments. We intend to publish as rapidly
as possible all updates/comments that contribute substantially to the topic
under discussion.
re-Prions David W. Colby1,* and Stanley B. Prusiner1,2 + Author
Affiliations
1Institute for Neurodegenerative Diseases, University of California, San
Francisco, San Francisco, California 94143 2Department of Neurology, University
of California, San Francisco, San Francisco, California 94143 Correspondence:
stanley@ind.ucsf.edu
Mule deer, white-tailed deer, and elk have been reported to develop CWD.
As the only prion disease identified in free-ranging animals, CWD appears to be
far more communicable than other forms of prion disease. CWD was first described
in 1967 and was reported to be a spongiform encephalopathy in 1978 on the basis
of histopathology of the brain. Originally detected in the American West, CWD
has spread across much of North America and has been reported also in South
Korea. In captive populations, up to 90% of mule deer have been reported to be
positive for prions (Williams and Young 1980). The incidence of CWD in cervids
living in the wild has been estimated to be as high as 15% (Miller et al. 2000).
The development of transgenic (Tg) mice expressing cervid PrP, and thus
susceptible to CWD, has enhanced detection of CWD and the estimation of prion
titers (Browning et al. 2004; Tamgüney et al. 2006). Shedding of prions in the
feces, even in presymptomatic deer, has been identified as a likely source of
infection for these grazing animals (Williams and Miller 2002; Tamgüney et al.
2009b). CWD has been transmitted to cattle after intracerebral inoculation,
although the infection rate was low (4 of 13 animals [Hamir et al. 2001]). This
finding raised concerns that CWD prions might be transmitted to cattle grazing
in contaminated pastures.
snip...
----- Original Message -----
From: David Colby To: flounder9@verizon.net
Cc: stanley@XXXXXXXX
Sent: Tuesday, March 01, 2011 8:25 AM
Subject: Re: FW: re-Prions David W. Colby1,* and Stanley B. Prusiner1,2 +
Author Affiliations
Dear Terry Singeltary,
Thank you for your correspondence regarding the review article Stanley
Prusiner and I recently wrote for Cold Spring Harbor Perspectives. Dr. Prusiner
asked that I reply to your message due to his busy schedule. We agree that the
transmission of CWD prions to beef livestock would be a troubling development
and assessing that risk is important. In our article, we cite a peer-reviewed
publication reporting confirmed cases of laboratory transmission based on
stringent criteria. The less stringent criteria for transmission described in
the abstract you refer to lead to the discrepancy between your numbers and ours
and thus the interpretation of the transmission rate. We stand by our assessment
of the literature--namely that the transmission rate of CWD to bovines appears
relatively low, but we recognize that even a low transmission rate could have
important implications for public health and we thank you for bringing attention
to this matter. Warm Regards, David Colby -- David Colby, PhDAssistant Professor
Department of Chemical Engineering University of Delaware
===========END...TSS==============
SNIP...SEE FULL TEXT ;
Friday, August 14, 2015
*** Susceptibility of cattle to the agent of chronic wasting disease from
elk after intracranial inoculation ***
*** 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.
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.
Prion and prion-like proteins are misfolded protein aggregates with the
ability to selfpropagate to spread disease between cells, organs and in some
cases across individuals. I n T r a n s m i s s i b l e s p o n g i f o r m
encephalopathies (TSEs), prions are mostly composed by a misfolded form of the
prion protein (PrPSc), which propagates by transmitting its misfolding to the
normal prion protein (PrPC). The availability of a procedure to replicate prions
in the laboratory may be important to study the mechanism of prion and
prion-like spreading and to develop high sensitive detection of small quantities
of misfolded proteins in biological fluids, tissues and environmental samples.
Protein Misfolding Cyclic Amplification (PMCA) is a simple, fast and efficient
methodology to mimic prion replication in the test tube. PMCA is a platform
technology that may enable amplification of any prion-like misfolded protein
aggregating through a seeding/nucleation process. In TSEs, PMCA is able to
detect the equivalent of one single molecule of infectious PrPSc and propagate
prions that maintain high infectivity, strain properties and species
specificity. Using PMCA we have been able to detect PrPSc in blood and urine of
experimentally infected animals and humans affected by vCJD with high
sensitivity and specificity. Recently, we have expanded the principles of PMCA
to amplify amyloid-beta (Aβ) and alphasynuclein (α-syn) aggregates implicated in
Alzheimer's and Parkinson's diseases, respectively. Experiments are ongoing to
study the utility of this technology to detect Aβ and α-syn aggregates in
samples of CSF and blood from patients affected by these diseases.
=========================
***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 prioncontaminated 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.
see ;
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.
Monday, November 3, 2014
Persistence of ovine scrapie infectivity in a farm environment following
cleaning and decontamination
PPo3-22:
Detection of Environmentally Associated PrPSc on a Farm with Endemic
Scrapie
Ben C. Maddison,1 Claire A. Baker,1 Helen C. Rees,1 Linda A. Terry,2 Leigh
Thorne,2 Susan J. Belworthy2 and Kevin C. Gough3 1ADAS-UK LTD; Department of
Biology; University of Leicester; Leicester, UK; 2Veterinary Laboratories
Agency; Surry, KT UK; 3Department of Veterinary Medicine and Science; University
of Nottingham; Sutton Bonington, Loughborough UK
Key words: scrapie, evironmental persistence, sPMCA
Ovine scrapie shows considerable horizontal transmission, yet the routes of
transmission and specifically the role of fomites in transmission remain poorly
defined. Here we present biochemical data demonstrating that on a
scrapie-affected sheep farm, scrapie prion contamination is widespread. It was
anticipated at the outset that if prions contaminate the environment that they
would be there at extremely low levels, as such the most sensitive method
available for the detection of PrPSc, serial Protein Misfolding Cyclic
Amplification (sPMCA), was used in this study. We investigated the distribution
of environmental scrapie prions by applying ovine sPMCA to samples taken from a
range of surfaces that were accessible to animals and could be collected by use
of a wetted foam swab. Prion was amplified by sPMCA from a number of these
environmental swab samples including those taken from metal, plastic and wooden
surfaces, both in the indoor and outdoor environment. At the time of sampling
there had been no sheep contact with these areas for at least 20 days prior to
sampling indicating that prions persist for at least this duration in the
environment. These data implicate inanimate objects as environmental reservoirs
of prion infectivity which are likely to contribute to disease transmission.
HIGHEST INFECTION RATE ON SEVERAL CWD CONFIRMED CAPTIVES
CHRONIC WASTING DISEASE CWD WISCONSIN Almond Deer (Buckhorn Flats) Farm
Update DECEMBER 2011
The CWD infection rate was nearly 80%, the highest ever in a North American
captive herd.
RECOMMENDATION: That the Board approve the purchase of 80 acres of land for
$465,000 for the Statewide Wildlife Habitat Program in Portage County and
approve the restrictions on public use of the site.
SUMMARY:
For Immediate Release Thursday, October 2, 2014
Dustin Vande Hoef 515/281-3375 or 515/326-1616 (cell) or
Dustin.VandeHoef@IowaAgriculture.gov
*** TEST RESULTS FROM CAPTIVE DEER HERD WITH CHRONIC WASTING DISEASE
RELEASED 79.8 percent of the deer tested positive for the disease
DES MOINES – The Iowa Department of Agriculture and Land Stewardship today
announced that the test results from the depopulation of a quarantined captive
deer herd in north-central Iowa showed that 284 of the 356 deer, or 79.8% of the
herd, tested positive for Chronic Wasting Disease (CWD).
*** see history of this CWD blunder here ;
On June 5, 2013, DNR conducted a fence inspection, after gaining approval
from surrounding landowners, and confirmed that the fenced had been cut or
removed in at least four separate locations; that the fence had degraded and was
failing to maintain the enclosure around the Quarantined Premises in at least
one area; that at least three gates had been opened;and that deer tracks were
visible in and around one of the open areas in the sand on both sides of the
fence, evidencing movement of deer into the Quarantined Premises.
The overall incidence of clinical CWD in white-tailed deer was 82%
Species (cohort) CWD (cases/total) Incidence (%) Age at CWD death (mo)
”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.
*** Federal indemnity funding became available in 2014. USDA APHIS
appraised the captive deer herd of 376 animals at that time, which was before
depopulation and testing, at $1,354,250.
*** At that time a herd plan was developed with the owners and officials
from USDA and the Iowa Department of Agriculture and Land Stewardship.
*** Once the depopulation was complete and the premises had been cleaned
and disinfected, indemnity of $917,100.00 from the USDA has been or will be paid
to the owners as compensation for the 356 captive deer depopulated.
SEE A FEW OF WISCONSIN CWD ENTITLEMENT PAYOUTS TO CAPTIVE OWNERS ;
$298,770 + $465,000
Sunday, January 17, 2016
Wisconsin Captive CWD Lotto Pays Out Again indemnity payment of $298,770
for 228 white-tailed deer killed on farm
this does not look good ;
Tuesday, January 19, 2016
Wisconsin Second CWD-positive deer found in Oneida County 5-year-old buck
shot at Three Lakes Trophy Ranch LLC agency received the CWD-positive report on
the animal Dec. 29
course in Texas, we still don’t know the true captive cwd count. more to
come there ;
Saturday, January 23, 2016
Texas new interim rule governing Deer Management Permit (DMP) activities as
part of the state’s response to the detection of chronic wasting disease (CWD)
in captive deer populations
Saturday, January 23, 2016
Texas Chronic Wasting Disease Response Update and Interim Deer Management
Permit Rules Recommended Adoption of Proposed Rules
or, just follow the money (see at bottom)
Thursday, January 21, 2016
INDIANA With end of long legal challenge last year, high-fence hunting
operations currently unregulated
Wednesday, October 07, 2015
Iowa DNR Meeting to Discuss Chronic Wasting Disease in Deer Set for Oct
13th in Bloomfield
Tuesday, January 20, 2015
Iowa Two Wild Deer Test Positive for Chronic Wasting Disease in Allamakee
County
Wednesday, April 09, 2014
Iowa : Chronic Wasting Disease Detected for First Time in Wild Iowa Deer
Sunday, January 24, 2016
IOWA CHRONIC WASTING TSE PRION DISEASE UPDATE
Wednesday, January 20, 2016
Exportation of Live Animals, Hatching Eggs, and Animal Germplasm From the
United States [Docket No. APHIS-2012-0049] RIN 0579-AE00 2016-00962
Thursday, January 14, 2016
*** EMERGING ANIMAL DISEASES Actions Needed to Better Position USDA to
Address Future Risks Report to the Chairman, Committee on Energy and Commerce,
House of Representatives December 2015 GAO-16-132
GAO
Friday, January 1, 2016
South Korea Lifts Ban on Beef, Veal Imports From Canada
US CONGRESS, another failed entity...tss
Tuesday, December 29, 2015
*** Congress repeals country-of-origin labeling rule for beef and pork
December 28, 2015 at 2:21am
*** Australian government assessing risk of importing beef from US, Japan
and the Netherlands
Thursday, December 24, 2015
Infectious disease spread is fueled by international trade
Thursday, December 17, 2015
Annual report of the Scientific Network on BSE-TSE 2015 EFSA-Q-2015-00738
10 December 2015
Sunday, October 18, 2015
World Organisation for Animal Health (OIE) and the Institut Pasteur
Cooperating on animal disease and zoonosis research
SSS SHOOT SHOVEL AND SHUT UP !
*** you can find some history of the BSE cases in Canada and Klein’s BSE
SSS policy comment here ;
Tuesday, August 12, 2014
MAD COW USDA TSE PRION COVER UP or JUST IGNORANCE, for the record AUGUST
2014
Saturday, December 12, 2015
*** BOVINE SPONGIFORM ENCEPHALOPATHY BSE TSE PRION REPORT DECEMBER 14, 2015
Thursday, October 22, 2015
Former Ag Secretary Ann Veneman talks women in agriculture and we talk mad
cow disease USDA and what really happened
*** 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 ;
Comments on technical aspects of the risk assessment were then submitted to
FSIS.
Comments were received from Food and Water Watch, Food Animal Concerns
Trust (FACT), Farm Sanctuary, R-CALF USA, Linda A Detwiler, and Terry S.
Singeltary.
This document provides itemized replies to the public comments received on
the 2005 updated Harvard BSE risk assessment. Please bear the following points
in mind:
Owens, Julie
From: Terry S. Singeltary Sr. [flounder9@verizon.net]
Sent: Monday, July 24, 2006 1:09 PM
To: FSIS RegulationsComments
Subject: [Docket No. FSIS-2006-0011] FSIS Harvard Risk Assessment of Bovine
Spongiform Encephalopathy (BSE)
Page 1 of 98
FSIS, USDA, REPLY TO SINGELTARY
Singeltary to APHIS FDA USDA et al ;
Sunday, January 17, 2016
Of Grave Concern Heidenhain Variant Creutzfeldt Jakob Disease
Terry S. Singeltary Sr.
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