Tuesday, January 26, 2016

USDA National Program 103 ANIMAL HEALTH TSE PRION ACCOMPLISHMENT REPORT 2011-2015 March 2015

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.

 

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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.

 

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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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