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Tuesday, June 16, 2015

Missouri MDC changes deer hunting regs to help slow CWD

MDC changes deer hunting regs to help slow CWD


CWD Management Area


Published on: Jun. 12, 2015

JEFFERSON CITY, Mo. – The Missouri Department of Conservation (MDC) is asking deer hunters in 19 central and northeastern Missouri counties to help limit the spread of a deadly deer disease through increased harvest opportunities this fall and winter. The Missouri Conservation Commission recently approved several changes to regulations for the upcoming 2015-16 fall deer hunting season that focus on slowing the spread of chronic wasting disease (CWD).

Chronic Wasting Disease infects only deer and other members of the deer family by causing degeneration of brain tissue, which slowly leads to death. The disease has no vaccine or cure and is 100-percent fatal.

"A primary way CWD is spread is through deer-to-deer contact," explained MDC State Wildlife Veterinarian Kelly Straka. "Deer gathering and interacting in larger numbers can potentially increase the spread in an area. Young bucks can also potentially spread the disease to new areas as they search for territories and mates."

REGULATION CHANGES


The regulation changes focus on slowing the spread of the disease in and around counties where CWD has been found. The changes will remove the antler-point restriction so hunters can harvest more young bucks. The changes will also increase the availability of firearms antlerless permits from 1 to 2 to help thin local deer numbers.

COUNTIES IMPACTED


These regulation changes add to similar measures MDC enacted in 2012 for six counties in northeastern Missouri after CWD was discovered in Linn and Macon counties. Counties affected by those regulation changes were Adair, Chariton, Linn, Macon, Randolph, and Sullivan.

The recent regulation changes add five more northeastern counties of Knox, Scotland, Schuyler, Shelby, and Putnam and come after six deer tested positive for CWD this past fall and winter in Adair County.

The recent regulation changes also include eight counties in central Missouri and come after a buck harvested in Cole County tested positive for the disease this past winter. Those counties are Boone, Callaway, Cole, Cooper, Miller, Moniteau, Morgan, and Osage.

"The challenge with CWD is that there is no way to fully eradicate the disease from an area once it has become established," said Dr. Straka. "While we do not expect short-term population impacts from the disease, CWD is likely to have serious long-term consequences to the health of Missouri's deer herd. Therefore, we have and will continue to focus on slowing the spread of the disease among deer in the affected areas, and trying to limit the spread to new areas of the state."

CWD TESTING RESULTS


The Missouri Department of Conservation (MDC) reports that a total of 16 new cases of CWD were found in free-ranging deer through its testing efforts this past fall and winter. Of the 16 new cases, nine were found in Macon County, six in Adair County, and one in Cole County.

These 16 new cases bring the total number of Missouri free-ranging deer that have tested positive for CWD to 26 overall since the disease was first discovered in the state in 2010.

MDC collected more than 3,400 tissue samples for CWD testing from harvested and other free-ranging deer this past fall and winter. The Department has collected more than 43,000 tissue samples since it began testing for the emerging disease in 2001. MDC will continue increased testing efforts this fall and winter in areas where CWD has been found.

MDC is also considering regulation changes for the 2016-17 deer season that would require testing of deer harvested during the opening weekend of the fall firearms season in the 19 counties in and around where CWD has been found.

DON'T TRANSPORT CARCASSES!


Dr. Straka said that hunters can also spread the disease by transporting and improperly disposing of potentially infected deer carcasses. She explained that CWD can be spread through carcass parts that contain brain, spinal cord, eyes, spleen, or lymph nodes.

"To help prevent the spread of diseases, such as CWD, we strongly discourage deer hunters from moving carcasses of harvested deer from the immediate area," she said.

"If possible, remove meat in the field and leave the carcass behind. If it's necessary to move the carcass before processing, place the remaining carcass parts after processing in trash bags and properly dispose of them through a trash service or landfill."

She added that some parts of a harvested deer are safe to move out of the immediate area.

"Items that are safe to transport are meat that is cut and wrapped, or has been boned out," she explained. "Also safe to transport are quarters or other portions of meat with no part of the spine or head attached, hides or capes from which all excess tissue has been removed, antlers including ones attached to skull plates or skulls that have been cleaned of all muscle and brain tissue, and finished taxidermy products."

MDC is considering regulation changes for the 2016-17 deer season that would prohibit the movement of carcass parts from the 19 counties in and around where CWD has been found and prohibit the importation of certain cervid carcass parts into Missouri.

AVOID FEEDING DEER


Dr. Straka added that MDC strongly discourages hunters and others from feeding or providing salt and minerals to deer.

"Feeding and mineral sites can concentrate deer from a broad area and place them in very close proximity to one another," she explained. "This can increase the transmission of the disease."

A regulation that prohibits the feeding of deer and placement of consumable products -- such as salt and mineral blocks -- that are intended to concentrate deer is already in effect in Adair, Chariton, Linn, Macon, Randolph, and Sullivan counties.

MDC is considering a regulation change for the 2016-17 deer season that would expand that regulation to include the 13 additional counties in northeastern and central Missouri in and around where CWD has been found.

PUBLIC COMMENTS WELCOME


MDC welcomes public comment on the regulation changes under consideration for the 2016-17 deer season. Comment online at mdc.mo.gov/node/6.

DEER HUNTING IN MISSOURI


Missouri offers some of the best deer hunting in the country, and deer hunting is an important part of many Missourians' lives and family traditions. The continued spread of CWD in Missouri is likely to reduce future hunting and wildlife-watching opportunities for Missouri's nearly 520,000 deer hunters and almost two million wildlife watchers. Deer hunting is also an important economic driver in Missouri and gives a $1 billion annual boost to the state and local economies.

DEER HUNTING DATES


Fall deer hunting season dates are as follows.

  • Archery: Sept. 15 to Nov. 13 and Nov. 25 to Jan. 15
  • Urban Firearms: Oct. 9 to 12
  • Youth Firearms: Oct. 31 and Nov. 1 and Jan. 2 and 3, 2016
  • November Firearms: Nov. 14 to 24
  • Antlerless Firearms: Nov. 25 to Dec. 6
  • Alternative Methods: Dec. 19 to 29

 


 

 

MDC reports two new cases of CWD found in Adair and Macon counties

 

Published on: Jan. 26, 2015

 

Posted by Joe Jerek

 

JEFFERSON CITY, Mo. -- The Missouri Department of Conservation (MDC) reports that two new cases of chronic wasting disease (CWD) have recently been found in north-central Missouri. One was found in an adult buck harvested by a hunter in Macon County and the other in an adult doe harvested by a hunter in Adair County. These two new cases bring the total of Missouri free-ranging deer that have tested positive for CWD to five for this hunting season and 15 overall. The total cases of CWD in Missouri captive and free-ranging deer now stands at 26.

 

CWD was first discovered in Missouri in 2010 at a private hunting preserve in Linn County. All cases of CWD in Missouri have been limited to Macon, Linn, and Adair counties, which are part of MDC's six-county CWD Containment Zone. Additional counties included in the zone are Chariton, Randolph, and Sullivan.

 


 

Monday, January 26, 2015

 

Missouri MDC reports two new cases of CWD found in Adair and Macon counties

 


 

LATE-BREAKING ABSTRACTS

 

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

 

Chronic wasting disease (CWD) is a widespread and expanding prion disease in free-ranging and captive cervid species in North America. The zoonotic potential of CWD prions is a serious public health concern. Current literature generated with in vitro methods and in vivo animal models (transgenic mice, macaques and squirrel monkeys) reports conflicting results. The susceptibility of human CNS and peripheral organs to CWD prions remains largely unresolved. In our earlier bioassay experiments using several humanized transgenic mouse lines, we detected protease-resistant PrPSc in the spleen of two out of 140 mice that were intracerebrally inoculated with natural CWD isolates, but PrPSc was not detected in the brain of the same mice. Secondary passages with such PrPSc-positive CWD-inoculated humanized mouse spleen tissues led to efficient prion transmission with clear clinical and pathological signs in both humanized and cervidized transgenic mice. Furthermore, a recent bioassay with natural CWD isolates in a new humanized transgenic mouse line led to clinical prion infection in 2 out of 20 mice. 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.

 

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***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.***

 

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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

 

The propensity for trans-species prion transmission is related to the structural characteristics of the enciphering and heterologous PrP, but the exact mechanism remains mostly mysterious. Studies of the effects of primary or tertiary prion protein structures on trans-species prion transmission have relied primarily upon animal bioassays, making the influence of prion protein structure vs. host co-factors (e.g. cellular constituents, trafficking, and innate immune interactions) difficult to dissect. As an alternative strategy, we used real-time quakinginduced conversion (RT-QuIC) to investigate trans-species prion conversion.

 

To assess trans-species conversion in the RT-QuIC system, we compared chronic wasting disease (CWD) and bovine spongiform encephalopathy (BSE) prions, as well as feline CWD (fCWD) and feline spongiform encephalopathy (FSE). Each prion was seeded into each host recombinant PrP (full-length rPrP of white-tailed deer, bovine or feline). We demonstrated that fCWD is a more efficient seed for feline rPrP than for white-tailed deer rPrP, which suggests adaptation to the new host.

 

Conversely, FSE maintained sufficient BSE characteristics to more efficiently convert bovine rPrP than feline rPrP. Additionally, human rPrP was competent for conversion by CWD and fCWD. ***This insinuates that, at the level of protein:protein interactions, the barrier preventing transmission of CWD to humans is less robust than previously estimated.

 

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***This insinuates that, at the level of protein:protein interactions, the barrier preventing transmission of CWD to humans is less robust than previously estimated.***

 

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Willingham, Erin McNulty, Kelly Anderson, Jeanette Hayes-Klug, Amy Nalls, and Candace Mathiason Colorado State University; Fort Collins, CO USA

 

Chronic wasting disease (CWD) is the transmissible spongiform encephalopathy (TSE), of free-ranging and captive cervids (deer, elk and moose).

 

The presence of infectious prions in the tissues, bodily fluids and environments of clinical and preclinical CWD-infected animals is thought to account for its high transmission efficiency. Recently it has been recognized that mother to offspring transmission may contribute to the facile transmission of some TSEs. Although the mechanism behind maternal transmission is not yet known, the extended asymptomatic TSE carrier phase (lasting years to decades) suggests that it may have implications in the spread of prions.

 

Placental trafficking and/or secretion in milk are 2 means by which maternal prion transmission may occur. In these studies we explore these avenues during early and late infection using a transgenic mouse model expressing cervid prion protein. Na€ıve and CWD-infected dams were bred at both timepoints, and were allowed to bear and raise their offspring. Milk was collected from the dams for prion analysis, and the offspring were observed for TSE disease progression. Terminal tissues harvested from both dams and offspring were analyzed for prions.

 

We have demonstrated that

 

(1) CWDinfected TgCerPRP females successfully breed and bear offspring, and

 

(2) the presence of PrPCWD in reproductive and mammary tissue from CWD-infected dams.

 

We are currently analyzing terminal tissue harvested from offspring born to CWD-infected dams for the detection of PrPCWD and amplification competent prions. These studies will provide insight into the potential mechanisms and biological significance associated with mother to offspring transmission of TSEs.

 

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P.157: Uptake of prions into plants

 

Christopher Johnson1, Christina Carlson1, Matthew Keating1,2, Nicole Gibbs1, Haeyoon Chang1, Jamie Wiepz1, and Joel Pedersen1 1USGS National Wildlife Health Center; Madison, WI USA; 2University of Wisconsin - Madison; Madison, WI USA

 

Soil may preserve chronic wasting disease (CWD) and scrapie infectivity in the environment, making consumption or inhalation of soil particles a plausible mechanism whereby na€ıve animals can be exposed to prions. Plants are known to absorb a variety of substances from soil, including whole proteins, yet the potential for plants to take up abnormal prion protein (PrPTSE) and preserve prion infectivity is not known. In this study, we assessed PrPTSE uptake into roots using laser scanning confocal microscopy with fluorescently tagged PrPTSE and we used serial protein misfolding cyclic amplification (sPMCA) and detect and quantify PrPTSE levels in plant aerial tissues. Fluorescence was identified in the root hairs of the model plant Arabidopsis thaliana, as well as the crop plants alfalfa (Medicago sativa), barley (Hordeum vulgare) and tomato (Solanum lycopersicum) upon exposure to tagged PrPTSE but not a tagged control preparation. Using sPMCA, we found evidence of PrPTSE in aerial tissues of A. thaliana, alfalfa and maize (Zea mays) grown in hydroponic cultures in which only roots were exposed to PrPTSE. Levels of PrPTSE in plant aerial tissues ranged from approximately 4 £ 10 ¡10 to 1 £ 10 ¡9 g PrPTSE g ¡1 plant dry weight or 2 £ 105 to 7 £ 106 intracerebral ID50 units g ¡1 plant dry weight. Both stems and leaves of A. thaliana grown in culture media containing prions are infectious when intracerebrally-injected into mice. ***Our results suggest that prions can be taken up by plants and that contaminated plants may represent a previously unrecognized risk of human, domestic species and wildlife exposure to prions.

 

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***Our results suggest that prions can be taken up by plants and that contaminated plants may represent a previously unrecognized risk of human, domestic species and wildlife exposure to prions.***

 

SEE ;

 

Friday, May 15, 2015

 

Grass Plants Bind, Retain, Uptake, and Transport Infectious Prions

 

Report

 


 

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P.19: Characterization of chronic wasting disease isolates from freeranging deer (Odocoileus sp) in Alberta and Saskatchewan, Canada

 

Camilo Duque Velasquez1, Chiye Kim1, Nathalie Daude1, Jacques van der Merwe1, Allen Herbst1, Trent Bollinger2, Judd Aiken1, and Debbie McKenzie1 1Centre for Prions and Protein Folding Diseases; University of Alberta; Edmonton, Canada; 2Western College of Veterinary Medicine; University of Saskatchewan; Saskatoon, Canada

 

Chronic wasting disease (CWD) is an emerging prion disease of free ranging and captive species of Cervidae. In North America, CWD is enzootic in some wild cervid populations and can circulate among different deer species. The contagious nature of CWD prions and the variation of cervid PRNP alleles, which influence host susceptibility, can result in the emergence and adaptation of different CWD strains. These strains may impact transmission host range, disease diagnosis, spread dynamics and efficacy of potential vaccines. We are characterizing different CWD agents by biochemical analysis of the PrPCWD conformers, propagation in vitro cell assays1 and by comparing transmission properties and neuropathology in Tg33 (Q95G96) and Tg60 (Q95S96) mice.2 Although Tg60 mice expressing S96- PrPC have been shown resistant to CWD infectivity from various cervid species,2,3

 

***these transgenic mice are susceptible to H95 C CWD, a CWD strain derived from experimental infection of deer expressing H95G96-PrPC. The diversity of strains present in free-ranging mule deer (Odocoileus hemionus) and white-tailed deer (Odocoileus virginianus) from Alberta and Saskatchewan is being determined and will allow us to delineate the properties of CWD agents circulating in CWD enzootic cervid populations of Canada.

 

References

 

1. van der Merwe J, Aiken J, Westaway D, McKenzie D. The standard scrapie cell assay: Development, utility and prospects. Viruses 2015; 7(1):180–198; PMID:25602372; http://dx.doi.org/10.3390/v7010180

 

2. Meade-White K, Race B, Trifilo M, Bossers A, Favara C, Lacasse R, Miller M, Williams E, Oldstone M, Race R, Chesebro B. Resistance to chronic wasting disease in transgenic mice expressing a naturally occurring allelic variant of deer prion protein. J Virol 2007; 81(9):4533–4539; PMID: 17314157; http://dx. doi.org/10.1128/JVI.02762-06

 

3. Race B, Meade-White K, Miller MW, Fox KA, Chesebro B. In vivo comparison of chronic wasting disease infectivity from deer with variation at prion protein residue 96. J Virol 2011; 85(17):9235–9238; PMID: 21697479; http://dx.doi.org/10.1128/JVI.00790-11

 

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***these transgenic mice are susceptible to H95 C CWD, a CWD strain derived from experimental infection of deer expressing H95G96-PrPC.

 

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P.136: Mother to offspring transmission of CWD—Detection in fawn tissues using the QuIC assay

 

Amy Nalls, Erin McNulty, Clare Hoover, Jeanette Hayes-Klug, Kelly Anderson, Edward Hoover, and Candace Mathiason Colorado State University; Fort Collins, CO USA

 

To investigate the role mother to offspring transmission plays in chronic wasting disease (CWD), we have employed a small, polyestrous breeding, indoor maintainable cervid model, the Reeves’ muntjac deer. Muntjac doe were inoculated with CWD and tested positive by lymphoid biopsy at 4 months post inoculation. From these CWD-infected doe, we obtained 3 viable fawns. These fawns tested IHC-positive for CWD by lymphoid biopsy as early as 40 d post birth, and all have been euthanized due to clinical disease at 31, 34 and 59 months post birth. The QuIC assay demonstrates sensitivity and specificity in the detection of conversion competent prions in peripheral IHC-positive tissues including tonsil, mandibular, partotid, retropharyngeal, and prescapular lymph nodes, adrenal gland, spleen and liver. In summary, using the muntjac deer model, we have demonstrated CWD clinical disease in offspring born to CWD-infected doe and found that the QuIC assay is an effective tool in the detection of prions in peripheral tissues. ***Our findings demonstrate that transmission of prions from mother to offspring can occur, and may be underestimated for all prion diseases.

 

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***Our findings demonstrate that transmission of prions from mother to offspring can occur, and may be underestimated for all prion diseases.

 

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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...

 

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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.

 

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31 Jan 2015 at 20:14 GMT

 

*** Ruminant feed ban for cervids in the United States? ***

 

31 Jan 2015 at 20:14 GMT

 


 

Friday, May 22, 2015

 

*** Chronic Wasting Disease and Program Updates - 2014 NEUSAHA Annual Meeting 12-14 May 2014 ***

 


 

Saturday, May 30, 2015

 

PRION 2015 ORAL AND POSTER CONGRESSIONAL ABSTRACTS

 


 


 

Wednesday, June 10, 2015

 

Zoonotic Potential of CWD Prions

 

LATE-BREAKING ABSTRACTS

 


 

 

PRION CONFERENCE 2014 HELD IN ITALY RECENTLY CWD BSE TSE UPDATE

 

> First transmission of CWD to transgenic mice over-expressing bovine prion protein gene (TgSB3985)

 

PRION 2014 - PRIONS: EPIGENETICS and NEURODEGENERATIVE DISEASES – Shaping up the future of prion research

 

Animal TSE Workshop 10.40 – 11.05 Talk Dr. L. Cervenakova First transmission of CWD to transgenic mice over-expressing bovine prion protein gene (TgSB3985)

 


 

 

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.

 

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.

 

P.28: Modeling prion species barriers and the new host effect using RT-QuIC

 

Kristen A Davenport, Davin M Henderson, Candace K Mathiason, and Edward A Hoover Prion Research Center; Colorado State University; Fort Collins, CO USA

 

The propensity for trans-species prion transmission is related to the structural characteristics of the enciphering and heterologous PrP, but the exact mechanism remains mostly mysterious.

 

Studies of the effects of primary or tertiary prion protein www.landesbioscience.com Prion 37 structures on trans-species prion transmission have relied upon animal bioassays, making the influence of prion protein structure vs. host co-factors (e.g. cellular constituents, trafficking, and innate immune interactions) difficult to dissect.

 

As an alternative strategy, we are using real-time quaking-induced conversion (RT-QuIC) to investigate the propensity for and the kinetics of trans-species prion conversion. RT-QuIC has the advantage of providing more defined conditions of seeded conversion to study the specific role of native PrP:PrPRES interactions as a component of the species barrier.

 

We are comparing chronic wasting disease (CWD) and bovine spongiform encephalopathy (BSE) prions by seeding each prion into its native host recPrP (full-length bovine recPrP, or white tail deer recPrP) vs. into the heterologous species.

 

Upon establishing the characteristics of intra-species and inter-species prion seeding for CWD and BSE prions, we will evaluate the seeding kinetics and cross-species seeding efficiencies of BSE and CWD passaged into a common new host—feline—shown to be a permissive host for both CWD and BSE.

 

*** We hypothesize that both BSE prions and CWD prions passaged through felines will seed human recPrP more efficiently than BSE or CWD from the original hosts, evidence that the new host will dampen the species barrier between humans and BSE or CWD. The new host effect is particularly relevant as we investigate potential means of trans-species transmission of prion disease.

 


 

 

Chronic Wasting Disease Susceptibility of Four North American Rodents

 

Chad J. Johnson1*, Jay R. Schneider2, Christopher J. Johnson2, Natalie A. Mickelsen2, Julia A. Langenberg3, Philip N. Bochsler4, Delwyn P. Keane4, Daniel J. Barr4, and Dennis M. Heisey2 1University of Wisconsin School of Veterinary Medicine, Department of Comparative Biosciences, 1656 Linden Drive, Madison WI 53706, USA 2US Geological Survey, National Wildlife Health Center, 6006 Schroeder Road, Madison WI 53711, USA 3Wisconsin Department of Natural Resources, 101 South Webster Street, Madison WI 53703, USA 4Wisconsin Veterinary Diagnostic Lab, 445 Easterday Lane, Madison WI 53706, USA *Corresponding author email: cjohnson@svm.vetmed.wisc.edu

 

We intracerebrally challenged four species of native North American rodents that inhabit locations undergoing cervid chronic wasting disease (CWD) epidemics. The species were: deer mice (Peromyscus maniculatus), white-footed mice (P. leucopus), meadow voles (Microtus pennsylvanicus), and red-backed voles (Myodes gapperi). The inocula were prepared from the brains of hunter-harvested white-tailed deer from Wisconsin that tested positive for CWD. Meadow voles proved to be most susceptible, with a median incubation period of 272 days. Immunoblotting and immunohistochemistry confirmed the presence of PrPd in the brains of all challenged meadow voles. Subsequent passages in meadow voles lead to a significant reduction in incubation period. The disease progression in red-backed voles, which are very closely related to the European bank vole (M. glareolus) which have been demonstrated to be sensitive to a number of TSEs, was slower than in meadow voles with a median incubation period of 351 days. We sequenced the meadow vole and red-backed vole Prnp genes and found three amino acid (AA) differences outside of the signal and GPI anchor sequences. Of these differences (T56-, G90S, S170N; read-backed vole:meadow vole), S170N is particularly intriguing due its postulated involvement in "rigid loop" structure and CWD susceptibility. Deer mice did not exhibit disease signs until nearly 1.5 years post-inoculation, but appear to be exhibiting a high degree of disease penetrance. White-footed mice have an even longer incubation period but are also showing high penetrance. Second passage experiments show significant shortening of incubation periods. Meadow voles in particular appear to be interesting lab models for CWD. These rodents scavenge carrion, and are an important food source for many predator species. Furthermore, these rodents enter human and domestic livestock food chains by accidental inclusion in grain and forage. Further investigation of these species as potential hosts, bridge species, and reservoirs of CWD is required.

 


 

please see ;

 


 

 

Monday, August 8, 2011

 

*** Susceptibility of Domestic Cats to CWD Infection ***

 

Oral.29: Susceptibility of Domestic Cats to CWD Infection

 

Amy Nalls, Nicholas J. Haley, Jeanette Hayes-Klug, Kelly Anderson, Davis M. Seelig, Dan S. Bucy, Susan L. Kraft, Edward A. Hoover and Candace K. Mathiason†

 

Colorado State University; Fort Collins, CO USA†Presenting author; Email: ckm@lamar.colostate.edu

 

Domestic and non-domestic cats have been shown to be susceptible to one prion disease, feline spongiform encephalopathy (FSE), thought to be transmitted through consumption of bovine spongiform encephalopathy (BSE) contaminated meat. Because domestic and free ranging felids scavenge cervid carcasses, including those in CWD affected areas, we evaluated the susceptibility of domestic cats to CWD infection experimentally. Groups of n = 5 cats each were inoculated either intracerebrally (IC) or orally (PO) with CWD deer brain homogenate. Between 40–43 months following IC inoculation, two cats developed mild but progressive symptoms including weight loss, anorexia, polydipsia, patterned motor behaviors and ataxia—ultimately mandating euthanasia. Magnetic resonance imaging (MRI) on the brain of one of these animals (vs. two age-matched controls) performed just before euthanasia revealed increased ventricular system volume, more prominent sulci, and T2 hyperintensity deep in the white matter of the frontal hemisphere and in cortical grey distributed through the brain, likely representing inflammation or gliosis. PrPRES and widely distributed peri-neuronal vacuoles were demonstrated in the brains of both animals by immunodetection assays. No clinical signs of TSE have been detected in the remaining primary passage cats after 80 months pi. Feline-adapted CWD was sub-passaged into groups (n=4 or 5) of cats by IC, PO, and IP/SQ routes. Currently, at 22 months pi, all five IC inoculated cats are demonstrating abnormal behavior including increasing aggressiveness, pacing, and hyper responsiveness.

 

*** Two of these cats have developed rear limb ataxia. Although the limited data from this ongoing study must be considered preliminary, they raise the potential for cervid-to-feline transmission in nature.

 


 


 

 

AD.63:

 

Susceptibility of domestic cats to chronic wasting disease

 

Amy V.Nalls,1 Candace Mathiason,1 Davis Seelig,2 Susan Kraft,1 Kevin Carnes,1 Kelly Anderson,1 Jeanette Hayes-Klug1 and Edward A. Hoover1 1Colorado State University; Fort Collins, CO USA; 2University of Minnesota; Saint Paul, MN USA

 

Domestic and nondomestic cats have been shown to be susceptible to feline spongiform encephalopathy (FSE), almost certainly caused by consumption of bovine spongiform encephalopathy (BSE)-contaminated meat. Because domestic and free-ranging nondomestic felids scavenge cervid carcasses, including those in areas affected by chronic wasting disease (CWD), we evaluated the susceptibility of the domestic cat (Felis catus) to CWD infection experimentally. Cohorts of 5 cats each were inoculated either intracerebrally (IC) or orally (PO) with CWD-infected deer brain. At 40 and 42 mo post-inoculation, two IC-inoculated cats developed signs consistent with prion disease, including a stilted gait, weight loss, anorexia, polydipsia, patterned motor behaviors, head and tail tremors, and ataxia, and progressed to terminal disease within 5 mo. Brains from these two cats were pooled and inoculated into cohorts of cats by IC, PO, and intraperitoneal and subcutaneous (IP/SC) routes. Upon subpassage, feline-adapted CWD (FelCWD) was transmitted to all IC-inoculated cats with a decreased incubation period of 23 to 27 mo. FelCWD was detected in the brains of all the symptomatic cats by western blotting and immunohistochemistry and abnormalities were seen in magnetic resonance imaging, including multifocal T2 fluid attenuated inversion recovery (FLAIR) signal hyper-intensities, ventricular size increases, prominent sulci, and white matter tract cavitation. Currently, 3 of 4 IP/SQ and 2 of 4 PO inoculared cats have developed abnormal behavior patterns consistent with the early stage of feline CWD.

 

*** These results demonstrate that CWD can be transmitted and adapted to the domestic cat, thus raising the issue of potential cervid-to- feline transmission in nature.

 


 

www.landesbioscience.com

 

PO-081: Chronic wasting disease in the cat— Similarities to feline spongiform encephalopathy (FSE)

 


 


 

 

FELINE SPONGIFORM ENCEPHALOPATHY FSE

 


 


 

 

2011

 

*** After a natural route of exposure, 100% of white-tailed deer were susceptible to scrapie.

 


 

 

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 ;

 

----- 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==============

 

 

Thursday, July 03, 2014

 

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

 


 

 

*** 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.

 


 

 


 

 

Terry S. Singeltary Sr.

 

 

 

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