Monday, June 23, 2014

PRION 2014 CHRONIC WASTING DISEASE CWD

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.

 

 P.89: Prions survive long-term burial in soil with some groundwater dissemination

 

Allister JA Smith,1 Karen Fernie,1 Ben Maddison,2 Keith Bishop,2 Kevin Gough,3 and Robert A Somerville1 1The Roslin Institute; University of Edinburgh; Edinburgh, UK; 2ADAS Biotechnology Group, University of Nottingham; Nottingham, UK; 3University of Nottingham; Nottingham, UK

 

An intrinsic property of prions is their extreme resistance to degradation. When they are deposited within the environment, whether from inappropriate disposal by man or from fallen diseased livestock, there is the potential to further propagate cases of disease for many years. It is evidenced that the spread of scrapie in sheep and chronic wasting disease in deer have occurred in this manner.

 

We mimicked such scenarios under large-scale field conditions to determine the extent to which TSE infectivity survives or disseminates in soil and soil water over five years. The mouse passaged BSE strain, 301V, was used to spike buried bovine heads, or was buried as an uncontained bolus in large soil-filled lysimeters. Two soils were examined, a free-draining sandy loam and a water-retentive clay loam.

 

Infectivity, determined by bioassay in mice, was recovered from all heads exhumed annually for 5 years from both soil types, with little reduction in the amount of infectivity over time. Small amounts of infectivity were found in soil samples immediately surrounding the heads but not in samples remote from them. Commensurate with this there was no evidence of significant lateral movement of infectivity from the bolus buried in a large soil mass. However large amounts of infectivity were recovered at the original bolus burial site in both soils. There was limited vertical upward movement of infectivity from the bolus buried in clay and downward movement from the bolus buried in sand perhaps reflecting the clay soils propensity to flood.

 

Throughout the course of the experiment rainwater particulate from several lysimeters was trapped on glass-fibre filters. Extracts from these filters were subject to serial PMCA (protein misfolding cyclic amplification) which was optimised using 301V-spiked samples and blinded controls. All positive and negative control samples were correctly determined. We have tested 44 samples from rainwater passed through the clay lysimeter filters, and found 9 positive samples, mainly from the initial 8 months of the experiment.

 

We conclude that TSE infectivity is likely to survive burial for long time periods with minimal loss of infectivity and limited movement from the original burial site. However PMCA results have shown that there is the potential for rainwater to elute TSErelated material from soil which could lead to the contamination of a wider area. These experiments reinforce the importance of risk assessment when disposing of TSE risk materials.

 

P.121: Efficient transmission of prion disease through environmental contamination

 

Sandra Pritzkow, Rodrigo Morales, and Claudio Soto Mitchell Center for Alzheimer’s disease and related Brain disorders; University of Texas Medical School at Houston; Hourston, TX USA

 

Chronic wasting disease (CWD) is a prion disorder effecting captive and free-ranging deer and elk. The efficient propagation suggests that horizontal transmission through contaminated environment may play an important role. It has been shown that infectious prions enter the environment through saliva, feces, urine, blood or placenta tissue from infected animals, as well as by carcasses from diseased animals and can stay infectious inside soil over several years.

 

82 Prion Volume 8 Supplement

 

We hypothesize that environmental components getting in contact with infectious prions can also play a role for the horizontal transmission of prion diseases. To study this issue, surfaces composed of various environmentally relevant materials were exposed to infectious prions and the attachment and retention of infectious material was studied in vitro and in vivo. We analyzed polypropylene, glass, stainless steel, wood, stone, aluminum, concrete and brass surfaces exposed to 263K-infected brain homogenate. For in vitro analyses, the material was incubated in serial dilutions of 263K-brain homogenate, washed thoroughly and analyzed for the presence of PrPSc by PMCA. The results show that even highly diluted PrPSc can bind efficiently to polypropylene, stainless steel, glass, wood and stone and propagate the conversion of normal prion protein. For in vivo experiments, hamsters were ic injected with implants incubated in 1% 263K-infected brain homogenate. Hamsters, inoculated with 263K-contaminated implants of all groups, developed typical signs of prion disease, whereas control animals inoculated with non-contaminated materials did not.

 

In addition, in order to study the transmission in a more natural setting, we exposed a group of hamster to habit in the presence of spheres composed of various materials that were pretreated with 263K prions. Many of the hamsters exposed to these contaminated materials developed typical signs of the disease that were confirmed by immunohistological and biochemical analyses.

 

These findings suggest that various surfaces can efficiently bind infectious prions and act as carriers of infectivity, suggesting that diverse elements in the environment may play an important role in horizontal prion transmission.

 

P.138: Phenotypic diversity in meadow vole (Microtus pennsylvanicus) prion diseases following challenge with chronic wasting disease isolates

 

Christopher J Johnson,1 Christina M Carlson,1,2 Jay R Schneider,1 Jamie K Wiepz,1 Crystal L Meyerett-Reid,3 Mark D Zabel,3 Joel A Pedersen,2 and Dennis M Heisey1 1USGS National Wildlife Health Center; Madison, WI USA; 2University of Wisconsin— Madison; Madison, WI USA; 3Colorado State University; Fort Collins, CO USA

 

Chronic wasting disease (CWD), a prion disease of cervids (deer, elk and moose), is spreading unchecked through large sections of North America. Transmission of CWD among cervids is especially facile and can occur through direct animal-toanimal contact and indirectly through contact with prions shed from infected animals. The disease transmission threat posed by CWD to other wildlife species remains unknown, but other species are inevitably exposed to CWD by consumption of infectious materials and through contact with environmental CWD contamination.

 

In this study, we investigated the transmission and adaptation of various white-tailed deer CWD isolates in the meadow vole (Microtus pennsylvanicus), a native North American rodent that is sympatric with current CWD epizootics that we have previously established is susceptible to CWD. We found that serial subpassage of CWD from white-tailed deer homozygous for glycine at position 96 (96GG) of the prion protein in meadow voles resulted in the selection of a single prion strain that was characterized by homogeneity in incubation period, abnormal prion protein (PrPTSE) glycoform ratio, lesion profile and PrPTSE deposition pattern. In contrast, passage of CWD from heterozygous 96GS genotype deer produced four unique disease phenotypes upon first passage. Subpassage of these types ultimately resulted in selection of a single strain by third passage that was distinct from the 96GG genotype CWD-derived strain.

 

We also establish that meadow voles are susceptible to CWD via peripheral challenge, albeit with lower attack rates and longer incubation periods. Interestingly, oral challenge of meadow voles with CWD resulted in subclinical infection in primary passage animals, but manifested as clinical prion disease upon subpassage.

 

Our data establish that meadow voles are permissive to CWD via peripheral exposure route, suggesting they could serve as an environmental reservoir for CWD. Additionally, our data are consistent with the hypothesis that at least two strains of CWD circulate in naturally-infected cervid populations and provide evidence that meadow voles are a useful tool for CWD strain typing.

 

 P.141: Abundant prion shedding in CWD-infected deer revealed by Realtime conversion

 

Edward A Hoover,1 Davin M Henderson,1 Nathaniel D Denkers,1 Candace K Mathiason,1 Matteo Manca,2,3 and Byron Caughey2 1Prion Research Center, Colorado State University; Fort Collins, CO USA; 2Laboratory of Persistent Viral Diseases, NI AID; Hamilton, MT USA; 3Department of Biomedical Sciences, University of Cagliari; Monserrato, Italy

 

Background/Introduction. Chronic wasting disease (CWD) is unique among prion diseases in its efficient lateral transmission in nature. While the presence of infectious prions in body fluids and excreta of infected cervids has been demonstrated by bioassay, the dynamics, magnitude, and consequences of prion shedding remain unknown. The present studies were undertaken to determine the kinetics, duration, and magnitude of prion shedding in infected white-tailed deer.

 

Materials and Methods. Longitudinal samples were collected from white-tailed deer over a 2-year span after either oral (n=11)] aerosol (n = 6) CWD exposure. The assay protocol employed phosphotungstic acid precipitation of either whole saliva or the pelleted fraction of urine to seed recombinant Syrian hamster prion PrP substrate in RT-QuIC reactions. Prion seeding activity was assayed in 8 replicates of each sample employing thioflavin T detection in a 96-well plate-based fluorometer. Prion seeding reaction rate was determined by taking the inverse of the time at which samples exceeded a threshold of 5 standard deviations above the mean fluorescence of negative controls (1/time to threshold). Seeding activity was quantitated by comparing the realtime conversion reaction rate to a standard curve derived from a reference bioassayed brain pool homogenate from deer with terminal CWD.

 

Results. We analyzed >200 longitudinally collected, blinded, then randomized saliva and urine samples from 17 CWDinfected and 3 uninfected white-tailed deer. We detected prion shedding as early as 3 months post exposure and sustained thereafter throughout the disease course in both aerosol and orally exposed deer. The incidence of non-specific false positive results from >500 saliva and urine samples from negative control deer was 0.8%. By comparing real-time reaction rates for these body fluids to a bioassayed serially diluted brain control, we estimated that ≤1 ml of saliva or urine from pre-symptomatic infected deer constitutes a lethal infectious prion dose.

 

Conclusion. CWD prions are shed in saliva and urine of infected deer as early as 3 months post infection and throughout the subsequent >1.5 year course of infection. In current work we are examining the relationship of prionemia to excretion and the impact of excreted prion binding to surfaces and particulates in the environment.

 

Acknowledgments. Support: NIH-RO1-NS-061902; Morris Animal Foundation D12ZO-045

 

 P.154: Urinary shedding of prions in Chronic Wasting Disease infected white-tailed deer

 

Nathaniel D Denkers,1 Davin M Henderson, 1 Candace K Mathiason,1 and Edward A Hoover1 1Prion Research Center, Department of Microbiology, Immunology, and Pathology, Colorado State University; Fort Collins, CO USA

 

Background/Introduction. Chronic wasting disease (CWD) is unique among prion diseases in its efficient lateral transmission in nature, yet the dynamics and magnitude of shedding and its immediate and long term consequences remain unknown. The present study was designed to determine the frequency and time span in which CWD prions are shed in urine from infected white-tailed deer using adapted real-time quaking-induced conversion (RT-QuIC) methodology.

 

Materials and Methods. Longitudinal urine samples were collected by free catch or catheterization over a 2-year period from oral-route infected [CWD+ (n = 11)] and aerosol-route-infected [CWD+ (n = 6); CWD- (n = 3)] white-tailed deer. High speed centrifugation pelleted material from 500 µl of urine was treated with sodium phosphotungstic acid (Na-PTA), resuspended in 0.05% SDS buffer, and used as seed in RT-QuIC assays employing recombinant Syrian hamster prion PrP substrate. Eight (8) replicates of each sample were run and prion seeding activity was recorded as thioflavin T binding fluorescence (480 nm emission) using a fluorimeter-shaker. Samples were considered positive if they crossed an established threshold (5 standard deviations above the negative mean fluorescence).

 

Results. In our oral-route inoculation studies, prion seeding activity has been demonstrated in urine collected at 6 months post-inoculation in 6 of 10 deer (11 of 80 replicates; 14%), and intermittently at later time points in all 11 CWD+ exposed deer. Our aerosol-route inoculation studies also showed prion seeding activity in urine collected at 6 months post-inoculation in 1 of 2 deer (3 of 16 replicates; 19%), and intermittently at later time points in 4 of 6 CWD+ exposed deer. Urine from sham-inoculated control deer and all baseline samples yielded 3 false-positive prion seeding activities (3 of 352 replicates; 0.8%).

 

Conclusion. CWD prions (as inferred by prion seeding activity by RT-QuIC) are shed in urine of infected deer as early as 6 months post inoculation and throughout the subsequent disease course. Further studies are in progress refining the real-time urinary prion assay sensitivity and we are examining more closely the excretion time frame, magnitude, and sample variables in relationship to inoculation route and prionemia in naturally and experimentally CWD-infected cervids.

 

Acknowledgments. Support: NIH: RO1-NS-061902 and Morris Animal Foundation: D12ZO-045

 

 P.158: Structurally and phenotypically different prions in CWD-infected white-tailed deer

 

Martin L Daus, Peter Lasch, and Michael Beekes Robert Koch-Institut; Berlin, Germany

 

Prions can exist as multiple strains within mammals. We could detect, for the first time, two distinct chronic wasting disease (CWD) isolates in white-tailed deer (WTD).

 

WTD had been challenged with CWD from either mule deer (MD) or WTD. Brain-derived prions from MD-infected WTD and WTD-infected WTD could be distinguished by biochemical, biophysical and biological methods. PK-mediated limited proteolysis at different pH-values indicated conformational differences between pathological prion proteins (PrPTSE) from MD-infected WTD and WTD-infected WTD. More specifically, Fouriertransform infrared microspectroscopy revealed secondary structure differences between highly purified PrPTSE extracts from MD-infected WTD and WTD-infected WTD. Different sedimentation velocities of PrPTSE in gradient centrifugations provided additional evidence for structure differences between prions from MD-infected WTD and WTD-infected WTD. Brain homogenate from WTD-infected WTD showed a substantially lower seeding activity on cellular prion protein (PrPC) of Syrian hamsters in protein misfolding cyclic amplification (PMCA) than its conformationally distinct counterpart from MD-infected WTD. When hamsters were intracerebrally inoculated with brain tissue from MD-infected WTD disease could be transmitted, which was not observed after similar inoculation with brain homogenate from WTD-infected WTD. In an ongoing macaque-study both CWD-isolates are currently being further tested for their transmissibility to primates.

 

P.163: Bayesian hierarchical modeling of chronic wasting disease in free-ranging white-tailed deer in the eastern U.S.

 

Tyler S Evans1 and W David Walter2 1Pennsylvania Cooperative Fish and Wildlife Research Unit; The Pennsylvania State University; University Park, PA USA; 2US Geological Survey; Pennsylvania Cooperative Fish and Wildlife Research Unit; The Pennsylvania State University; University Park, PA USA

 

Introduction. Chronic wasting disease (CWD) is a prion disease that affects both free-ranging and captive cervid populations. In the past 45 years, CWD has spread from a single region in Colorado to all bordering states, as well as Canada, the Midwest and the northeastern United States. In 2005, CWD was detected in the eastern U.S. in a free-ranging white-tailed deer (Odocoileus virginianus) killed by a vehicle in West Virginia followed by positives from Virginia, Maryland, and Pennsylvania. Although considerable information has been learned about CWD in wildlife from several areas of the U.S. and Canada, little information is available on spatial epidemiology of disease in the eastern U.S.

 

Materials and Methods. In order to develop a CWD surveillance plan for the region, we determined covariates and the best scale for analysis by exploring habitat use and estimating the mean size of home range for deer in the central Appalachian region (6 km2). We conducted Bayesian hierarchical modeling in WinBUGS on 24 a priori models using 11,320 free-ranging white-tailed deer (69 positive, 11,251 negative) that have been tested for CWD since 2005. Testing for CWD was conducted using standard protocols on a variety of tissues extracted from hunter-harvested deer that included retropharyngeal lymph nodes, tonsil lymph nodes, and the medulla oblongata sectioned at the obex.

 

Results. We found 94% of models weights were accounted for in our top model that identified habitats such as developed and open as covariates that increased the odds of infection for CWD in this region. Contrary to research in the endemic area of Colorado, we did not identify clay soil as a significant predictor of disease even though clay soil ranged from 9% to 19% in our study samples. Furthermore, contrary to results from the recent expansion of CWD into the agricultural Midwestern U.S. (Wisconsin, Illinois), we identified developed and open habitats were better predictors of disease occurrence compared to forest habitat considered more critical to deer population dynamics in the U.S.

 

Conclusions. Our results suggested that the odds of infection for CWD is likely controlled by areas that congregate deer thus increasing direct transmission (deer-to-deer interactions) or indirect transmission (deer-to-environment) by sharing or depositing infectious prion proteins in these preferred habitats. Epidemiology of CWD in the eastern U.S. is likely controlled by separate factors than found in the Midwestern and endemic areas for CWD and can assist in performing more efficient surveillance efforts for the region.

 

P.178: Longitudinal quantitative analysis of CWD prions shed in saliva of deer

 

Davin M Henderson, Nina Garbino, Nathaniel D Denkers, Amy V Nalls, Candace K Mathiason, and Edward A Hoover Prion Research Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University; Fort Collins, CO USA

 

Background/Introduction. Chronic Wasting Disease (CWD) is an emergent rapidly spreading fatal prion disease of cervids (deer, elk and moose). CWD has now been identified in 22 States (including two new states within the last year), 2 Canadian provinces, and South Korea. Shedding of infectious prions in excreta (saliva, urine, feces) may be an important factor in CWD transmission. Here we apply an adapted version of a rapid in vitro assay [real-time quaking-induced conversion (RT-QuIC)] to determine the time of onset, length, pattern, and magnitude of prion shedding in saliva of infected deer.

 

Materials and Methods. The RT-QuIC assay was performed as previously described in Henderson et al. PLoS-One (2013). Saliva samples were quantitated by comparison to a RT-QuIC reaction rate standard curve of a bioassayed obex sample from a terminally ill cervid.

 

Results. To better understand the onset and length of CWD prion shedding we analyzed >150 longitudinally collected, blinded, then randomized saliva samples from 17 CWD-infected and 3 uninfected white-tailed deer. We observed prion shedding, as detected by the RT-QuIC assay, as early as 3 months from inoculation and sustained shedding throughout the disease course in both aerosol and orally exposed deer. We estimated the infectious lethal dose of prions shed in saliva from infected deer by comparing real-time reaction rates of saliva samples to a bioassayed serially diluted brain control. Our results indicate that as little as 1 ml of saliva from pre-symptomatic infected deer constitutes a lethal CWD prion dose.

 

Conclusions. During the pre-symptomatic stage of CWD infection and throughout the course of disease deer may be shedding multiple LD50 doses per day in their saliva. CWD prion shedding through saliva and excreta may account for the unprecedented spread of this prion disease in nature.

 

Acknowledgments. Supported by NIH grant RO1-NS-061902 and grant D12ZO-045 from the Morris Animal Foundation.

 


 

Monday, June 23, 2014

 

PRION 2014 TYPICAL AND ATYPICAL BSE AND CJD REPORT UPDATES

 


 

 Sunday, June 22, 2014

 

Governor Nixon Missouri Urged to VETO Legislation turning over captive shooting pens to USDA

 

snip...

 

PLEASE WATCH THIS VIDEO OF A CAPTIVE SHOOTING PEN HUNT.

 

THIS IS NOT HUNTING FOLKS, THIS IS JUST SLAUGHTERING A DEFENSELESS ANIMAL, AND HAVING TO PROP IT UP TO DO THAT $$$

 

Michigan 2005 237 captive shooting pens not in compliance

 

March 2005 DNR Audit

 

37 % or 237 captive pens not in compliance.

 

96% that died were not tested for CWD, as was required.

 

700 captive pens had inadequate fencing.

 

tranquilizing target deer...

 

Measuring antlers to verify scores for record book.

 

Scooping up with front in loading tractor, and dumping into small 3 to 5 acre pen to be shot for up to $20,000.00

 

how did the fix the problem, turned the DNR over to the USDA et al, problem solved...

 

‘’The rich...who are content to buy what they have not the skill to get by their own exertions, these are the real enemies of game’’

 

Theodore Roosevelt’s Principles of the Hunt

 


 

snip...see full text ;

 


 

Infectious agent of sheep scrapie may persist in the environment for at least 16 years

 

Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3

 


 

New studies on the heat resistance of hamster-adapted scrapie agent: Threshold survival after ashing at 600°C suggests an inorganic template of replication

 


 

Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production

 


 

Detection of protease-resistant cervid prion protein in water from a CWD-endemic area

 


 

A Quantitative Assessment of the Amount of Prion Diverted to Category 1 Materials and Wastewater During Processing

 


 

Rapid assessment of bovine spongiform encephalopathy prion inactivation by heat treatment in yellow grease produced in the industrial manufacturing process of meat and bone meals

 


 

PPo4-4:

 

Survival and Limited Spread of TSE Infectivity after Burial

 


 

Sunday, September 01, 2013

 

hunting over gut piles and CWD TSE prion disease

 


 

Sunday, April 13, 2014

 

Mineral licks: motivational factors for visitation and accompanying disease risk at communal use sites of elk and deer

 

Environmental Geochemistry and Health

 


 

Alkaline Hydrolysis

 

The alkaline hydrolysis process has been through a validation study by the Institute of Animal Health, and an Opinion has been issued by the Scientific Steering Committee of the European Commission (EC 2002) on the effectiveness of the process. There was detectable infectivity from samples held for 3 hours, but not from samples held for 6 hours. The committee concluded that the by-products after 3 hours of processing could contain some residual TSE infectivity and that this risk may decrease with increased duration of processing.

 

Glossary

 

snip...see ;

 


 

Alkaline Hydrolysis

 


 


 

========================================

 

There are many disposal options for dead livestock currently in use throughout the world; however, the knowledge that TSEs and some pathogens may not be completely destroyed may limit their utility in the wake of changing legislation (e.g. the amended EU Animal By-Products Regulation (1069/2009) which comes into effect in March 2011). On-farm disposal methods are favoured by the farming community due to the perceived environmental, practical, economical and biosecurity benefits, therefore processes such as composting and anaerobic digestion have found favour in countries such as the USA and Canada. Under the ABPR in the EU, these options are not deemed safe;

 

========================================

 

Review

 

The environmental and biosecurity characteristics of livestock carcass disposal methods: A review

 

Ceri L. Gwyther a, A. Prysor Williams a,⇑, Peter N. Golyshin b, Gareth Edwards-Jones a, David L. Jones a a School of Environment, Natural Resources and Geography, College of Natural Sciences, Bangor University, Gwynedd, LL57 2UW, UK b School of Biological Sciences, College of Natural Sciences, Bangor University, Gwynedd, LL57 2UW, UK

 

a b s t r a c t

 

Livestock mortalities represent a major waste stream within agriculture. Many different methods are used throughout the world to dispose of these mortalities; however within the European Union (EU) disposal options are limited by stringent legislation. The legal disposal options currently available to EU farmers (primarily rendering and incineration) are frequently negatively perceived on both practical and economic grounds. In this review, we assess the potential environment impacts and biosecurity risks associated with each of the main options used for disposal of livestock mortalities in the world and critically evaluate the justification for current EU regulations. Overall, we conclude that while current legislation intends to minimise the potential for on-farm pollution and the spread of infectious diseases (e.g. transmissible spongiform encephalopathies, bacterial pathogens), alternative technologies (e.g. bioreduction, anaerobic digestion) may provide a more cost-effective, practical and biosecure mechanism for carcass disposal as well as having a lower environmental footprint. Further social, environmental and economic research is therefore warranted to assess the holistic benefits of alternative approaches for carcass disposal in Europe, with an aim to provide policy-makers with robust knowledge to make informed decisions on future legislation.

 

snip...

 

4. Conclusions

 

There are many disposal options for dead livestock currently in use throughout the world; however, the knowledge that TSEs and some pathogens may not be completely destroyed may limit their utility in the wake of changing legislation (e.g. the amended EU Animal By-Products Regulation (1069/2009) which comes into effect in March 2011). On-farm disposal methods are favoured by the farming community due to the perceived environmental, practical, economical and biosecurity benefits, therefore processes such as composting and anaerobic digestion have found favour in countries such as the USA and Canada. Under the ABPR in the EU, these options are not deemed safe; however, the legal alternatives are not favoured by the farming community leading to widespread non-compliance and potentially greater environmental risk (due to illegal dumping, etc. (Kirby et al., 2010)). There is therefore a real need for new methods to be developed and validated and the legislation reconsidered following submission of new evidence. From this perspective, bioreduction and freezing seems to be promising on-farm storage methods for livestock mortalities, limiting the need for off farm transport thus reducing associated biosecurity risks. While the implementation of highly precautionary, risk-averse mortality disposal systems is admirable in many ways, similar risk assessments and legislation do not apply to other components of the livestock sector which may pose a similar or even greater risk to human health or environmental contamination (e.g. spreading of animal waste, animal access to watercourses, public access to grazing land). It is important therefore that mortality disposal systems are based on a realistic and proportionate level of acceptable risk in comparison to other components of the food chain, rather than the current zero-risk approach. It is clear that more evidence is needed on each disposal and storage method in order to make substantiated risk assessments, e.g. the effects of spreading carcass ash on crops or the potential of leachate from burial to contaminate ground or surface water. This review has initiated this process by applying a simple five-star award system to each livestock disposal and storage method (Table 3 and Table 4, respectively) in order to rudimentarily classify various biosecurity and environmental factors based on current scientific evidence. Methods in need of greater research have also been highlighted where there is either limited or no existing published literature. Further research into the economic impacts of dead livestock disposal is necessary for legislators to appreciate the cost implications on the livestock sector, whilst life-cycle assessments are needed to help provide more environmentally sustainable disposal solutions.

 


 

Sunday, November 3, 2013

 

Environmental Impact Statements; Availability, etc.: Animal Carcass Management [Docket No. APHIS-2013-0044]

 


 

Saturday, March 15, 2014

 

Potential role of soil properties in the spread of CWD in western Canada

 


 

Friday, February 08, 2013

 

*** Behavior of Prions in the Environment: Implications for Prion Biology

 


 

OPINION AND REPORT ON : THE TREATMENT OF ANIMAL WASTE BY MEANS OF HIGH TEMPERATURE (150°C, 3 HOURS) AND CORRESPONDING HIGH PRESSURE ALKALINE HYDROLYSIS.

 

ADOPTED BY THE SCIENTIFIC STEERING COMMITTEE AT ITS MEETING OF 16 MAY 2002

 


 

FINAL OPINION AND REPORT ON : A TREATMENT OF ANIMAL WASTE BY MEANS OF HIGH TEMPERATURE (150°C, 3 HOURS) AND HIGH PRESSURE ALKALINE HYDROLYSIS.

 

ADOPTED BY THE SCIENTIFIC STEERING COMMITTEE AT ITS MEETING OF 10-11 APRIL 2003

 


 

BSE INQUIRY 1989 TO ...

 

The BSE Inquiry / Statement No 19B (supplementary) Dr Alan Colchester Issued 06/08/1999 (not scheduled to give oral evidence)

 

SECOND STATEMENT TO THE BSE INQUIRY

 

Dr A Colchester BA BM BCh PhD FRCP Reader in Neurosciences & Computing, University of Kent at Canterbury; Consultant Neurologist, Guy’s Hospital London and William Harvey Hospital Ashford April 1999

 

snip...

 

88. Natural decay: Infectivity persists for a long time in the environment. A study by Palsson in 1979 showed how scrapie was contracted by healthy sheep, after they had grazed on land which had previously been grazed by scrapie-infected sheep, even though the land had lain fallow for three years before the healthy sheep were introduced. Brown also quoted an early experiment of his own (1991), where he had buried scrapie-infected hamster brain and found that he could still detect substantial infectivity three years later near where the material had been placed. 89. Potential environmental routes of infection: Brown discusses the various possible scenarios, including surface or subsurface deposits of TSE-contaminated material, which would lead to a build-up of long-lasting infectivity. Birds feeding on animal remains (such as gulls visiting landfill sites) could disperse infectivity. Other animals could become vectors if they later grazed on contaminated land. "A further question concerns the risk of contamination of the surrounding water table or even surface water channels, by effluents and discarded solid wastes from treatment plants. A reasonable conclusion is that there is a potential for human infection to result from environmental contamination by BSE-infected tissue residues. The potential cannot be quantified because of the huge numbers of uncertainties and assumptions that attend each stage of the disposal process". These comments, from a long established authority on TSEs, closely echo my own statements which were based on a recent examination of all the evidence. 90. Susceptibility: It is likely that transmissibility of the disease to humans in vivo is probably low, because sheep that die from scrapie and cattle that die from BSE are probably a small fraction of the exposed population. However, no definitive data are available.

 

91. Recommendations for disposal procedures: Brown recommends that material which is actually or potentially contaminated by BSE should be: 1) exposed to caustic soda; 2) thoroughly incinerated under carefully inspected conditions; and 3) that any residue should be buried in landfill, to a depth which would minimise any subsequent animal or human exposure, in areas that would not intersect with any potable water-table source.

 

92. This review and recommendations from Brown have particular importance. Brown is one of the world's foremost authorities on TSEs and is a senior researcher in the US National Institutes of Health (NIH). It is notable that such a respected authority is forthright in acknowledging the existence of potential risks, and in identifying the appropriate measures necessary to safeguard public health. Paper by SM Cousens, L Linsell, PG Smith, Dr M Chandrakumar, JW Wilesmith, RSG Knight, M Zeidler, G Stewart, RG Will, "Geographical distribution of variant CJD in the UK (excluding Northern Ireland)". Lancet 353:18-21, 2 nd January 1999 93. The above paper {Appendix 41 (02/01/99)} (J/L/353/18) examined the possibility that patients with vCJD (variant CJD) might live closer to rendering factories than would be expected by chance. All 26 cases of vCJD in the UK with onset up to 31 st August 1998 were studied. The incubation period of vCJD is not known but by analogy with other human TSEs could lie within the range 5-25 years. If vCJD had arisen by exposure to rendering products, such exposure might plausibly have occurred 8-10 years before the onset of symptoms. The authors were able to obtain the addresses of all rendering plants in the UK which were in production in 1988. For each case of vCJD, the distance from the place of residence on 1st January 1998 to the nearest rendering plant was calculated

 

snip...

 


 

BSE INQUIRY DATA 1989 through the 1990’s REPORT ON BOVINE CARCASE INCINERATION, incinerations temps., plume, etc. ...tss

 

some unofficial info. from a source on the inside looking out;

 

Confidential!!!!

 

As early as 1992-3 there had been long studies conducted on small pastures containing scrapie infected sheep at the sheep research station associated with the Neuropathogenesis Unit in Edinburgh, Scotland. Whether these are documented...I don't know. But personal recounts both heard and recorded in a daily journal indicate that leaving the pastures free and replacing the topsoil completely at least 2 feet of thickness each year for SEVEN years....and then when very clean (proven scrapie free) sheep were placed on these small pastures.... the new sheep also broke with scrapie and passed it to offspring. I am not sure that TSE contaminated ground could ever be free of the agent!! A very frightening revelation!!!

 

xxxxxxxxxxx

 

you can take that with however many grains of salt you wish, and we can debate these issues all day long, but bottom line, this is not rocket-science, all one has to do is some experiments and case studies, but for the life of me, i don't know what they are waiting on?

 

kind regards, Terry S. Singeltary Sr., Bacliff, Texas USA

 

more here;

 


 


 

INCINERATION TEMPS

 

requirements include;

 

a. after burning to the range of 800 to 1000*C to eliminate smell;

 

well heck, this is just typical public relations fear factor control. do you actually think they would spend the extra costs for fuel, for such extreme heat, just to eliminate smell, when they spread manure all over your veg's. i think not. what they really meant were any _TSE agents_.

 

b. Gas scrubbing to eliminate smoke -- though steam may be omitted;

 

c. Stacks to be fitted with grit arreaters;

 

snip...

 

1.2 Visual Imact

 

It is considered that the requirement for any carcase incinerator disign would be to ensure that the operations relating to the reception, storage and decepitation of diseased carcasses must not be publicly visible and that any part of a carcase could not be removed or interfered with by animals or birds.

 

REPORT ON BOVINE CARCASE INCINERATION

 

IF GOD DEMANDED

 

full text;

 


 


 

snip...see more ;

 


 

 

spreading cwd around...tss

 

Between 1996 and 2002, chronic wasting disease was diagnosed in 39 herds of farmed elk in Saskatchewan in a single epidemic. All of these herds were depopulated as part of the Canadian Food Inspection Agency’s (CFIA) disease eradication program. Animals, primarily over 12 mo of age, were tested for the presence CWD prions following euthanasia. Twenty-one of the herds were linked through movements of live animals with latent CWD from a single infected source herd in Saskatchewan, 17 through movements of animals from 7 of the secondarily infected herds.

 

***The source herd is believed to have become infected via importation of animals from a game farm in South Dakota where CWD was subsequently diagnosed (7,4). A wide range in herd prevalence of CWD at the time of herd depopulation of these herds was observed. Within-herd transmission was observed on some farms, while the disease remained confined to the introduced animals on other farms.

 


 

spreading cwd around...tss

 

Friday, May 13, 2011

 

Chronic Wasting Disease (CWD) outbreaks and surveillance program in the Republic of Korea Chronic Wasting Disease (CWD) outbreaks and surveillance program in the Republic of Korea

 

Hyun-Joo Sohn, Yoon-Hee Lee, Min-jeong Kim, Eun-Im Yun, Hyo-Jin Kim, Won-Yong Lee, Dong-Seob Tark, In- Soo Cho, Foreign Animal Disease Research Division, National Veterinary Research and Quarantine Service, Republic of Korea

 

Chronic wasting disease (CWD) has been recognized as an important prion disease in native North America deer and Rocky mountain elks. The disease is a unique member of the transmissible spongiform encephalopathies (TSEs), which naturally affects only a few species. CWD had been limited to USA and Canada until 2000.

 

On 28 December 2000, information from the Canadian government showed that a total of 95 elk had been exported from farms with CWD to Korea. These consisted of 23 elk in 1994 originating from the so-called “source farm” in Canada, and 72 elk in 1997, which had been held in pre export quarantine at the “source farm”.Based on export information of CWD suspected elk from Canada to Korea, CWD surveillance program was initiated by the Ministry of Agriculture and Forestry (MAF) in 2001.

 

All elks imported in 1997 were traced back, however elks imported in 1994 were impossible to identify. CWD control measures included stamping out of all animals in the affected farm, and thorough cleaning and disinfection of the premises. In addition, nationwide clinical surveillance of Korean native cervids, and improved measures to ensure reporting of CWD suspect cases were implemented.

 

Total of 9 elks were found to be affected. CWD was designated as a notifiable disease under the Act for Prevention of Livestock Epidemics in 2002.

 

Additional CWD cases - 12 elks and 2 elks - were diagnosed in 2004 and 2005.

 

Since February of 2005, when slaughtered elks were found to be positive, all slaughtered cervid for human consumption at abattoirs were designated as target of the CWD surveillance program. Currently, CWD laboratory testing is only conducted by National Reference Laboratory on CWD, which is the Foreign Animal Disease Division (FADD) of National Veterinary Research and Quarantine Service (NVRQS).

 

In July 2010, one out of 3 elks from Farm 1 which were slaughtered for the human consumption was confirmed as positive. Consequently, all cervid – 54 elks, 41 Sika deer and 5 Albino deer – were culled and one elk was found to be positive. Epidemiological investigations were conducted by Veterinary Epidemiology Division (VED) of NVRQS in collaboration with provincial veterinary services.

 

Epidemiologically related farms were found as 3 farms and all cervid at these farms were culled and subjected to CWD diagnosis. Three elks and 5 crossbreeds (Red deer and Sika deer) were confirmed as positive at farm 2.

 

All cervids at Farm 3 and Farm 4 – 15 elks and 47 elks – were culled and confirmed as negative.

 

Further epidemiological investigations showed that these CWD outbreaks were linked to the importation of elks from Canada in 1994 based on circumstantial evidences.

 

In December 2010, one elk was confirmed as positive at Farm 5. Consequently, all cervid – 3 elks, 11 Manchurian Sika deer and 20 Sika deer – were culled and one Manchurian Sika deer and seven Sika deer were found to be positive. This is the first report of CWD in these sub-species of deer. Epidemiological investigations found that the owner of the Farm 2 in CWD outbreaks in July 2010 had co-owned the Farm 5.

 

In addition, it was newly revealed that one positive elk was introduced from Farm 6 of Jinju-si Gyeongsang Namdo. All cervid – 19 elks, 15 crossbreed (species unknown) and 64 Sika deer – of Farm 6 were culled, but all confirmed as negative.

 

: Corresponding author: Dr. Hyun-Joo Sohn (+82-31-467-1867, E-mail: shonhj@korea.kr) 2011 Pre-congress Workshop: TSEs in animals and their environment 5

 


 


 


 

Friday, May 13, 2011

 

Chronic Wasting Disease (CWD) outbreaks and surveillance program in the Republic of Korea

 


 

 

how many states have $465,000., and can quarantine and purchase there from, each cwd said infected farm, but how many states can afford this for all the cwd infected cervid game ranch type farms, and this is just one cwd infected farm, which had the highest documented infection rate of cwd, documented at 80%.

 

Tuesday, December 20, 2011

 

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:

 


 

Friday, April 04, 2014

 

Wisconsin State officials kept silent on CWD discovery at game farm

 


 

Tuesday, March 25, 2014

 

Transmission of Chronic Wasting Disease in Wisconsin White-Tailed Deer: Implications for Disease Spread and Management

 

*** However, we also note that CWD transmission rates and prevalence are much higher in captive deer farms than has been reported in wild populations [67].

 


 

Tuesday, February 11, 2014

 

*** Wisconsin tracks 81 deer from game farm with CWD buck to seven other states

 


 

Monday, December 02, 2013

 

WISCONSIN CHRONIC WASTING DISEASE CWD DISCOVERED MARATHON COUNTY HUNTING PRESERVE

 


 

Tuesday, December 17, 2013

 

Wisconsin Second CWD positive deer found in Grant County

 


 

Friday, February 03, 2012

 

Wisconsin Farm-Raised Deer Farms and CWD there from 2012 report Singeltary et al

 


 

2010 WISCONSIN CAPTIVE DEER ESCAPES

 

There were 26 reported escape incidents so far this year, this amounted to 20 actual confirmed escape incidents because 3 were previously reported, 2 were confirmed as wild deer, and 1 incident was not confirmed. ...

 

snip...

 

C. & D. Captive Cervid and Law Enforcement Update (11:10 AM)- Warden Pete Dunn gave the captive cervid farm update.

 

There were 26 reported escape incidents so far this year, this amounted to 20 actual confirmed escape incidents because 3 were previously reported, 2 were confirmed as wild deer, and 1 incident was not confirmed. Approximately 30% of these escapes were caused by gates being left open and the other 70% resulted from bad fencing or fence related issues. The 20 actual confirmed escape incidents amounted to 77 total animals. 50 of the escaped animals were recovered or killed and 27 were not recovered and remain unaccounted for. Last year the CWD Committee passed a resolution to require double gates, but this has not gone into effect yet. Questions were raised by the committee about double fencing requirements? Pete responded that double fencing has not been practical or accepted by the industry. The DNR has the authority to do fence inspections. ? If a fence fails to pass the inspection the fencing certificate can be revoked and the farmer can be issued a citation. This year three citations and one warning have been issued for escapes. Pete reviewed the reporting requirements for escape incidents that these must be reported within 24 hours. The farmer then has 72 hours to recover the animals or else it will affect the farm’s herd status and ability to move animals. Davin proposed in the 15 year CWD Plan that the DNR take total control and regulatory authority over all deer farm fencing. Larry Gohlke asked Pete about the reliability for reporting escapes? Pete said that the majority of escapes were reported by the farmer, but it is very difficult to determine when an escape actually occurred. Pete said that they are more concerned that an escape is reported and not that it is reported at the exact time that it happened.

 


 

Wisconsin : 436 Deer Have Escaped From Farms to Wild

 

Date: March 18, 2003 Source: Milwaukee Journal Sentinel

 

Contacts: LEE BERGQUIST lbergquist@journalsentinel.com

 

State finds violations, lax record keeping at many sites, report says

 

A state inspection of private deer farms, prompted by the discovery of chronic wasting disease, found that 436 white-tailed deer escaped into the wild, officials said Tuesday

 

The Department of Natural Resources found that captive deer have escaped from one-third of the state's 550 deer farms over the lifetime of the operations. The agency also uncovered hundreds of violations and has sought a total of 60 citations or charges against deer farm operators.

 

snip...

 

CWD found on 2 farms

 

Seven deer have tested positive for the disease on game farms - one on a Portage County farm and six on a Walworth County farm - since the disease was discovered in three wild deer killed near Mount Horeb in western Dane County. One deer that tested positive on the Walworth County farm escaped and roamed free for six months.

 

snip...

 

The audit found that most farms were in compliance, but the DNR found many violations and instances of poor record keeping. Also in numerous instances, fences did not stop wild and captive deer from intermingling.

 

At least 227 farms conducted part of their business on a cash basis, making it hard to track animal movement with financial records.

 

For example, both the Internal Revenue Service and the state Department of Revenue have been contacted about a deer farm near Wild Rose in Waushara County that is suspected of selling six large bucks for $45,000 in cash and not using live deer shipping tags as required.

 

The DNR found that game farm operators have more deer in captivity than their records show, which is "due in part because the owners of a number of large deer farm operations were! unable to accurately count the number of deer within their fences," the audit found.

 

Hundreds of deer escape

 

The DNR found a total of 671 deer that escaped farms - 436 of which were never found - because of storm-damaged fences, gates being left open or the animals jumping over or through fences.

 

In one example in Kewaunee County, a deer farmer's fence was knocked down in a summer storm. Ten deer escaped, and the farmer told the DNR he had no intention of trying to reclaim them. The DNR found five of the deer, killed them and cited the farmer for violation of a regulation related to fencing.

 

Another deer farmer near Mishicot, in Manitowoc County, released all nine of his whitetails last summer after he believed the discovery of chronic wasting disease was going to drive down the market for captive deer.

 

The DNR found 24 instances of unlicensed deer farms and issued 19 citations.

 

Journal Sentinel correspondent Kevin Murphy contributed to this report.

 

Game Farms Inspected

 

A summary of the findings of the Department of Natural Resources' inspection of 550 private white-tailed deer farms in the state: The deer farms contained at least 16,070 deer, but the DNR believes there are more deer in captivity than that because large deer farms are unable to accurately count their deer. 671 deer had escaped from game farms, including 436 that were never found.

 

24 farmers were unlicensed. One had been operating illegally since 1999 after he was denied a license because his deer fence did not meet minimum specifications.

 

Records maintained by operators ranged from "meticulous documentation to relying on memory." At least 227 farms conducted various portions of their deer farm business with cash. Over the last three years, 1,222 deer died on farms for various reasons. Disease testing was not performed nor required on the majority of deer. Farmers reported doing business with people in 22 other states and one Canadian province. Click these links for more information

 


 

The initial discovery at Wilderness Whitetails was the first in five years. In trying to explain the sudden appearance, McGraw cited several possibilities for transmission, including the chance it occurred spontaneously.

 

That drew attention of Clausen and wildlife staff at the DNR. Clausen said he knew of no peer-reviewed research showing the disease turned up that way.

 

Tami Ryan, wildlife health section chief with the DNR, asked the agriculture department to back up the claim.

 

Richard Bourie, a veterinarian, pointed to a paper by Nobel Laureate Stanley Prusiner of the University of California, San Francisco, who discussed spontaneous occurrence in TSEs.

 

*** Ryan wrote back and said, "to the best of our collective knowledge, spontaneous CWD in wild deer has not been substantiated," although she said the DNR wasn't trying to pick a fight.

 

Said McGraw: "There is no battle going on here. We all read science here. Everybody looks at different possibilities."

 


 

Saturday, February 04, 2012

 

*** Wisconsin 16 age limit on testing dead deer Game Farm CWD Testing Protocol Needs To Be Revised

 

Approximately 4,200 fawns, defined as deer under 1 year of age, were sampled from the eradication zone over the last year. The majority of fawns sampled were between the ages of 5 to 9 months, though some were as young as 1 month.

 

*** Two of the six fawns with CWD detected were 5 to 6 months old.

 

All six of the positive fawns were taken from the core area of the CWD eradication zone where the highest numbers of positive deer have been identified.

 


 

Wednesday, September 04, 2013

 

***cwd - cervid captive livestock escapes, loose and on the run in the wild...

 


 

”The occurrence of CWD must be viewed against the contest of the locations in which it occurred. It was an incidental and unwelcome complication of the respective wildlife research programmes. Despite it’s subsequent recognition as a new disease of cervids, therefore justifying direct investigation, no specific research funding was forthcoming. The USDA veiwed it as a wildlife problem and consequently not their province!” ...page 26.

 


 

Sunday, January 06, 2013

 

USDA TO PGC ONCE CAPTIVES ESCAPE

 

*** "it‘s no longer its business.”

 


 

Monday, June 24, 2013

 

The Effects of Chronic Wasting Disease on the Pennsylvania Cervid Industry Following its Discovery

 


 

Tuesday, May 20, 2014

 

“Atypical” Chronic Wasting Disease in PRNP Genotype 225FF Mule Deer

 


 

Tuesday, May 27, 2014

 

New Missouri CWD regulations... You know where we stand... What are your thoughts?

 


 

Friday, May 30, 2014

 

Wisconsin Waushara County hunting preserve ordered to pay civil forfeiture in CWD case

 


 

Monday, May 05, 2014

 

Member Country details for listing OIE CWD 2013 against the criteria of Article 1.2.2., the Code Commission recommends consideration for listing

 


 

Program Standards: Chronic Wasting Disease Herd Certification Program and Interstate Movement of Farmed or Captive Deer, Elk, and Moose DOCUMENT ID: APHIS-2006-0118-0411

 

***Singeltary submission

 


 


 

*** 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.

 


 

Sunday, May 18, 2014

 

*** Chronic Wasting Disease CWD TSE PRION DISEASE and the transmission to other species

 


 

*** 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).

 


 

Saturday, April 19, 2014

 

Exploring the zoonotic potential of animal prion diseases: In vivo and in vitro approaches

 


 

 

TSS

posted by Terry S. Singeltary Sr. at 2:25 PM

0 Comments:

Post a Comment

Subscribe to Post Comments [Atom]

<< Home