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Diagnostic accuracy of rectal mucosa biopsy testing for chronic wasting disease within white-tailed deer (Odocoileus virginianus

Posted Aug 24 2012 1:55pm
Diagnostic accuracy of rectal mucosa biopsy testing for chronic wasting disease within white-tailed deer (Odocoileus virginianus) herds in North America



Effects of age, sex, polymorphism at PRNP codon 96, and disease progression


Bruce... V. Thomsen1 David A. Schneider Katherine I. O’Rourke Thomas Gidlewski James McLane Robert W. Allen Alex A. McIsaac Gordon B. Mitchell Delwyn P. Keane Terry R. Spraker Aru Balachandran


U.S. Department of Agriculture, National Veterinary Services Laboratories, Ames, IA (Thomsen)


U.S. Department of Agriculture, Agricultural Research Service, Pullman, WA (Schneider, O’Rourke)


U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, Fort Collins, CO (Gidlewski)


Canadian Food Inspection Agency, Battleford, Saskatchewan, Canada (McLane)


Canadian Food Inspection Agency, Prince Albert, Saskatchewan, Canada (Allen)


Canadian Food Inspection Agency, Saskatoon, Saskatchewan, Canada (McIsaac)


National and OIE Reference Laboratory for Scrapie and CWD, Canadian Food Inspection Agency, Ottawa Laboratory–Fallowfield, Ottawa, Ontario, Canada (Mitchell, Balachandran)


University of Wisconsin, Wisconsin Veterinary Diagnostic Laboratory, Madison, WI (Keane)


Colorado State University Diagnostic Laboratory, Fort Collins, CO (Spraker)


↵1 Bruce V. Thomsen, National Veterinary Services Laboratories, 1920 Dayton Avenue, Ames, IA 50010. bruce.v.thomsen@aphis.usda.gov



Abstract



An effective live animal diagnostic test is needed to assist in the control of chronic wasting disease (CWD), which has spread through captive and wild herds of white-tailed deer (Odocoileus virginianus) in Canada and the United States. In the present study, the diagnostic accuracy of rectal mucosa biopsy sample testing was determined in white-tailed deer from 4 CWD-infected captive herds. Specifically, the current study compared the immunohistochemical detection of disease-associated prion protein in postmortem rectal mucosa biopsy samples to the CWD status of each deer as determined by immunodiagnostic evaluations of the brainstem at the obex, the medial retropharyngeal lymph node, and the palatine tonsil. The effects of age, sex, genotype, and disease progression were also evaluated. Diagnostic sensitivity on rectal biopsy samples for CWD in white-tailed deer ranged from 63% to 100%; the pooled estimate of sensitivity was 68% with 95% confidence limits (95% CLs) of 49% and 82%. However, diagnostic sensitivity was dependent on genotype at prion protein gene (PRNP) codon 96 and on disease progression as assessed by obex grade. Diagnostic sensitivity was 76% (95% CLs: 49%, 91%) for 96GG deer but only 42% (95% CLs: 13%, 79%) for 96GS deer. Furthermore, diagnostic sensitivity was only 36% for deer in the earliest stage of disease (obex grade 0) but was 100% for deer in the last 2 stages of preclinical disease (obex grades 3 and 4). The overall diagnostic specificity was 99.8%. Selective use of antemortem rectal biopsy sample testing would provide valuable information during disease investigations of CWD-suspect deer herds.







*** Spraker suggested an interesting explanation for the occurrence of CWD. The deer pens at the Foot Hills Campus were built some 30-40 years ago by a Dr. Bob Davis. At or abut that time, allegedly, some scrapie work was conducted at this site. When deer were introduced to the pens they occupied ground that had previously been occupied by sheep.


(PLEASE NOTE SOME OF THESE OLD UK GOVERNMENT FILE URLS ARE SLOW TO OPEN, AND SOMETIMES YOU MAY HAVE TO CLICK ON MULTIPLE TIMES, PLEASE BE PATIENT, ANY PROBLEMS PLEASE WRITE ME PRIVATELY, AND I WILL TRY AND FIX OR SEND YOU OLD PDF FILE...TSS)





Wednesday, February 16, 2011


IN CONFIDENCE


SCRAPIE TRANSMISSION TO CHIMPANZEES


IN CONFIDENCE






PO-039: A comparison of scrapie and chronic wasting disease in white-tailed deer


Justin Greenlee, Jodi Smith, Eric Nicholson US Dept. Agriculture; Agricultural Research Service, National Animal Disease Center; Ames, IA USA






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








High-Fence 226-Inch Whitetail Escapes, Shot in Louisiana


by Dylan Polk•December 1, 2011






Volume 18, Number 3—March 2012



Synopsis


Occurrence, Transmission, and Zoonotic Potential of Chronic Wasting Disease


Samuel E. Saunders1, Shannon L. Bartelt-Hunt, and Jason C. Bartz Author affiliations: University of Nebraska-Lincoln, Omaha, Nebraska, USA (S.E. Saunders, S.L. Bartelt-Hunt); Creighton University, Omaha (J.C. Bartz)


snip...


CWD has been identified in free-ranging cervids in 15 US states and 2 Canadian provinces and in ≈100 captive herds in 15 states and provinces and in South Korea (Figure 1, panel B). Except in South Korea, CWD has not been detected outside North America. In most locations reporting CWD cases in free-ranging animals, the disease continues to emerge in wider geographic areas, and prevalence appears to be increasing in many disease-endemic areas. Areas of Wyoming now have an apparent CWD prevalence of near 50% in mule deer, and prevalence in areas of Colorado and Wisconsin is <15 0="0" 10="10" 5="5" according="according" adult="adult" age="age" agencies.="agencies." and="and" appear="appear" areas="areas" between="between" but="but" cwd="cwd" data="data" deer.="deer." deer="deer" div="div" elk="elk" factors="factors" for="for" from="from" gene="gene" genetic="genetic" highest="highest" however="however" in="in" include="include" influence="influence" influences="influences" is="is" known="known" less="less" lower="lower" male="male" many="many" obtained="obtained" of="of" parts="parts" polymorphisms="polymorphisms" prevalence="prevalence" provincial="provincial" prp="prp" reaches="reaches" remain="remain" remains="remains" reports="reports" risk="risk" scrapie.="scrapie." sex="sex" show="show" state="state" strong="strong" susceptibility="susceptibility" than="than" the="the" to="to" understood="understood" wildlife="wildlife" wyoming.="wyoming.">

snip...


Long-term effects of CWD on cervid populations and ecosystems remain unclear as the disease continues to spread and prevalence increases. In captive herds, CWD might persist at high levels and lead to complete herd destruction in the absence of human culling. Epidemiologic modeling suggests the disease could have severe effects on free-ranging deer populations, depending on hunting policies and environmental persistence (8,9). CWD has been associated with large decreases in free-ranging mule deer populations in an area of high CWD prevalence (Boulder, Colorado, USA) (5). In addition, CWD-infected deer are selectively preyed upon by mountain lions (5), and may also be more vulnerable to vehicle collisions (10).


snip...


Conclusions


Much remains unknown about prion diseases and CWD in particular, especially about CWD strains (which may have varied zoonotic potentials) and the long-term effects of CWD on cervid ecosystems. CWD prevalence and geographic range appear likely to continue to increase. Moreover, the disease is inevitably fatal, and no effective therapeutic measures are presently available. As such, it would seem wise to continue research and surveillance of CWD to elucidate the details of its transmission, pathogenesis, and continued emergence in cervid populations in hopes that strategies for mitigating its negative effects on humans and cervid ecosystems can be identified.









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.



Despite the five year premise plan and site decontamination, The WI DNR has concerns over the bioavailability of infectious prions at this site to wild white-tail deer should these fences be removed. Current research indicates that prions can persist in soil for a minimum of 3 years.


However, Georgsson et al. (2006) concluded that prions that produced scrapie disease in sheep remained bioavailable and infectious for at least 16 years in natural Icelandic environments, most likely in contaminated soil.


Additionally, the authors reported that from 1978-2004, scrapie recurred on 33 sheep farms, of which 9 recurrences occurred 14-21 years after initial culling and subsequent restocking efforts; these findings further emphasize the effect of environmental contamination on sustaining TSE infectivity and that long-term persistence of prions in soils may be substantially greater than previously thought. < < <








SNIP...SEE FULL TEXT ;








50 GAME FARMS IN USA INFECTED WITH CHRONIC WASTING DISEASE CWD


2012


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.


Despite the five year premise plan and site decontamination, The WI DNR has concerns over the bioavailability of infectious prions at this site to wild white-tail deer should these fences be removed. Current research indicates that prions can persist in soil for a minimum of 3 years.


However, Georgsson et al. (2006) concluded that prions that produced scrapie disease in sheep remained bioavailable and infectious for at least 16 years in natural Icelandic environments, most likely in contaminated soil.


Additionally, the authors reported that from 1978-2004, scrapie recurred on 33 sheep farms, of which 9 recurrences occurred 14-21 years after initial culling and subsequent restocking efforts; these findings further emphasize the effect of environmental contamination on sustaining TSE infectivity and that long-term persistence of prions in soils may be substantially greater than previously thought




SNIP...SEE FULL TEXT ;









Thursday, February 09, 2012


50 GAME FARMS IN USA INFECTED WITH CHRONIC WASTING DISEASE







Friday, February 03, 2012


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








Saturday, February 04, 2012


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







Monday, June 11, 2012


OHIO Captive deer escapees and non-reporting








Ohio's testing is spontaneous and voluntary, and is limited to 16 month old only, and only after found dead. so, the flaws there are obvious. anything voluntary is useless, and the voluntary mad cow feed ban proved just how useless anything voluntary is. ...








Friday, July 20, 2012


CWD found for first time in Iowa at hunting preserve











TSS
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