Chronic Wasting Disease CWD TSE prion update

Discussion in 'Wildlife Diseases' started by flounder, Aug 17, 2014.

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



    Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3



    http://jgv.sgmjournals.org/content/87/12/3737.full



    *** 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 TSE related 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.



    *** 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.



    PRION 2014 CONFERENCE



    CHRONIC WASTING DISEASE CWD



    A FEW FINDINGS ;



    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.



    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 TSE related 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.



    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.



    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.



    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.



    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.



    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.



    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.



    see full text and more ;



    Monday, June 23, 2014



    *** PRION 2014 CONFERENCE CHRONIC WASTING DISEASE CWD



    https://www.landesbioscience.com/journals/prion/6.Poster_Topic 2_Prion Diseases in Animals.pdf



    http://chronic-wasting-disease.blogspot.com/2014/06/prion-2014-chronic-wasting-disease-cwd.html



    Tuesday, July 01, 2014



    *** CHRONIC WASTING DISEASE CWD TSE PRION DISEASE, GAME FARMS, AND POTENTIAL RISK FACTORS THERE FROM ***



    http://chronic-wasting-disease.blogspot.com/2014/07/chronic-wasting-disease-cwd-tse-prion.html



    Thursday, July 03, 2014



    *** How Chronic Wasting Disease is affecting deer population and what’s the risk to humans and pets? ***



    http://chronic-wasting-disease.blogspot.com/2014/07/how-chronic-wasting-disease-is.html



    Saturday, August 02, 2014



    *** Structural effects of PrP polymorphisms on intra- and inter-species prion transmission



    In contrast, the scrapie prions used in the deer transmission studies of Greenlee and colleagues were isolated from a sheep encoding A136, ***raising the possibility that deer may be susceptible to multiple scrapie strains.



    snip...



    Significance



    The unpredictable recurrences of prion epidemics, their incurable lethality, and the capacity of animal prions to infect humans, provide significant motivation to ascertain the parameters governing disease transmission. The unprecedented spread, and uncertain zoonotic potential of chronic wasting disease (CWD), a contagious epidemic among deer, elk, and other cervids, is of particular concern. Here we demonstrate that naturally occurring primary structural differences in cervid PrPs differentially impact the efficiency of intra- and interspecies prion transmission. Our results not only deliver new information about the role of primary structural variation on prion susceptibility, but also provide functional support to a mechanism in which plasticity of a tertiary structural epitope governs prion protein conversion and intra- and inter-species susceptibility to prions.-



    snip...



    http://chronic-wasting-disease.blogspot.com/2014/08/structural-effects-of-prp-polymorphisms.html



    *** 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.



    http://cdmrp.army.mil/prevfunded/nprp/NPRP_Summit_Final_Report.pdf



    Wednesday, July 23, 2014



    After the storm? UK blood safety and the risk of variant Creutzfeldt-Jakob Disease



    http://vcjd.blogspot.com/2014/07/after-storm-uk-blood-safety-and-risk-of.html



    Sunday, June 29, 2014



    Transmissible Spongiform Encephalopathy TSE Prion Disease North America 2014



    http://transmissiblespongiformencep.../transmissible-spongiform-encephalopathy.html



    Tuesday, August 12, 2014



    MAD COW USDA TSE PRION COVER UP or JUST IGNORANCE, for the record AUGUST 2014



    http://madcowusda.blogspot.com/2014/08/mad-cow-usda-tse-prion-cover-up-or-just.html



    kind regards, terry
     
    Last edited by a moderator: Aug 17, 2014

  2. Ya know I have said a number of times, why do we have deer farms anyway- outlaw them, they are not needed,
     
  3. seems to me Texas deer expert has notjhing to do with keeping deer farms legal in Wi ???????????????