Zoonotic Potential of CWD: Experimental Transmissions to Non-Human Primates

Envt.06: Zoonotic Potential of CWD: Experimental Transmissions to Non-Human Primates

Emmanuel Comoy,1,† Valérie Durand,1 Evelyne Correia,1 Aru Balachandran,2 Jürgen Richt,3 Vincent Beringue,4 Juan-Maria Torres,5 Paul Brown,1 Bob Hills6 and Jean-Philippe Deslys1

1Atomic Energy Commission; Fontenay-aux-Roses, France; 2Canadian Food Inspection Agency; Ottawa, ON Canada; 3Kansas State University; Manhattan, KS USA; 4INRA; Jouy-en-Josas, France; 5INIA; Madrid, Spain; 6Health Canada; Ottawa, ON Canada†Presenting author; Email: emmanuel.comoy@cea.fr

The constant increase of chronic wasting disease (CWD) incidence in North America raises a question about their zoonotic potential. A recent publication showed their transmissibility to new-world monkeys, but no transmission to old-world monkeys, which are phylogenetically closer to humans, has so far been reported. Moreover, several studies have failed to transmit CWD to transgenic mice overexpressing human PrP.

Bovine spongiform encephalopathy (BSE) is the only animal prion disease for which a zoonotic potential has been proven. We described the transmission of the atypical BSE-L strain of BSE to cynomolgus monkeys, suggesting a weak cattle-to-primate species barrier. We observed the same phenomenon with a cattle-adapted strain of TME (Transmissible Mink Encephalopathy). Since cattle experimentally exposed to CWD strains have also developed spongiform encephalopathies, we inoculated brain tissue from CWD-infected cattle to three cynomolgus macaques as well as to transgenic mice overexpressing bovine or human PrP. Since CWD prion strains are highly lymphotropic, suggesting an adaptation of these agents after peripheral exposure, a parallel set of four monkeys was inoculated with CWD-infected cervid brains using the oral route.

Nearly four years post-exposure, monkeys exposed to CWD-related prion strains remain asymptomatic. In contrast, bovinized and humanized transgenic mice showed signs of infection, suggesting that CWD-related prion strains may be capable of crossing the cattle-to-primate species barrier. Comparisons with transmission results and incubation periods obtained after exposure to other cattle prion strains (c-BSE, BSE-L, BSE-H and cattle-adapted TME) will also be presented, in order to evaluate the respective risks of each strain.

link url not available, please see PRION 2011 ;

http://www.prion2011.ca/files/PRION_2011_-_Posters_(May_5-11).pdf



Greetings,

I believe the statement and quote below is incorrect ;

"CWD has been transmitted to cattle after intracerebral inoculation, although the infection rate was low (4 of 13 animals [Hamir et al. 2001]). This finding raised concerns that CWD prions might be transmitted to cattle grazing in contaminated pastures."

Please see ;

Within 26 months post inoculation, 12 inoculated animals had lost weight, revealed abnormal clinical signs, and were euthanatized. Laboratory tests revealed the presence of a unique pattern of the disease agent in tissues of these animals. These findings demonstrate that when CWD is directly inoculated into the brain of cattle, 86% of inoculated cattle develop clinical signs of the disease.

http://www.ars.usda.gov/research/publications/publications.htm?seq_no_115=194089


"although the infection rate was low (4 of 13 animals [Hamir et al. 2001])."

shouldn't this be corrected, 86% is NOT a low rate. ...

kindest regards,

Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518


MARCH 1, 2011

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, PhD Assistant Professor Department of Chemical Engineering University of Delaware

====================END...TSS==============

SEE FULL TEXT ;

Wednesday, January 5, 2011

ENLARGING SPECTRUM OF PRION-LIKE DISEASES Prusiner Colby et al 2011

Prions

David W. Colby1,* and Stanley B. Prusiner1,2

http://betaamyloidcjd.blogspot.com/2011/01/enlarging-spectrum-of-prion-like.html


Sunday, June 26, 2011

Risk Analysis of Low-Dose Prion Exposures in Cynomolgus Macaque

http://transmissiblespongiformencephalopathy.blogspot.com/2011/06/risk-analysis-of-low-dose-prion.html


Thursday, June 23, 2011

Experimental H-type bovine spongiform encephalopathy characterized by plaques and glial- and stellate-type prion protein deposits

http://transmissiblespongiformencephalopathy.blogspot.com/2011/06/experimental-h-type-bovine-spongiform.html


Saturday, June 25, 2011

Transmissibility of BSE-L and Cattle-Adapted TME Prion Strain to Cynomolgus Macaque

"BSE-L in North America may have existed for decades"

http://transmissiblespongiformencephalopathy.blogspot.com/2011/06/transmissibility-of-bse-l-and-cattle.html



Sunday, May 01, 2011

STUDY OF ATYPICAL BSE 2010 Annual Report May 2011

http://bse-atypical.blogspot.com/2011/05/study-of-atypical-bse-2010-annual.html


TSS