Chronic Wasting Disease Found In A White-Tailed Deer In Maryland
Posted Nov 27 2011 12:10pm
Chronic Wasting Disease Found In A White-Tailed Deer In Maryland
Annapolis, Md. (February 10, 2011) — The Maryland Department of Natural Resources (DNR) received laboratory confirmation on February 10, 2011 that a white-tailed deer harvested in Maryland tested positive for chronic wasting disease (CWD). This is the first confirmed case of CWD in Maryland. A hunter in Allegany County reported taking the deer on November 27, 2010 in Green Ridge State Forest. Maryland joins 20 other states and Canadian provinces with CWD documented in deer, elk or moose.
"Our team of wildlife professionals has been preparing for this result for some time so we are well-informed and ready to limit the impact of this event,” said Paul Peditto, Director of DNR’s Wildlife and Heritage Service. “We have sampled intensively for this disease since 2002 and see this as an unfortunate but somewhat inevitable outcome. The good news is that our preparation and planning ensure a sound scientific foundation for our response to this single positive test result. With the continued cooperation of hunters, farmers, deer processors and landowners who have supported our monitoring effort, we will manage this deer disease consistent with the best available science and with minimal impact on our deer population and the people who enjoy these great animals.”
“Concerns over CWD should not stop anyone from enjoying venison,” added Peditto, who explained that only four species of the deer family are known to be susceptible to CWD: elk, mule deer, moose and white-tailed deer. Of these, only the white-tailed deer occurs in the wild in Maryland and there are no reported cases of transmission to humans or other animals.
As always, hunters are advised to exercise caution and never consume the meat of sick animals. Hunters are also advised to avoid contact with the brain, spinal column or lymph nodes of deer — all of which are normally removed during the butchering process.
This is the first positive sample out of nearly 6,800 deer tested in Maryland since 1999. From 2002 until 2009 that sampling occurred statewide. In 2010, sampling efforts were focused on Allegany and western Washington counties due to the presence of positive cases in nearby West Virginia and Virginia. West Virginia first detected CWD in Hampshire County in 2005 and it was found in Frederick County, Virginia in early 2010.
“Maryland will continue to work closely with the wildlife professionals in our adjacent states to share information and coordinate response efforts. However, our primary goal is to ensure the public is fully-informed and knows what we know when we know it. We want to be certain that every interested Marylander understands this disease and recognizes that there is no risk to people, pets or domestic livestock. As in every other state with CWD, we will respond appropriately while ultimately learning to live with this disease with little impact to our wildlife or citizens,” Peditto concluded.
For more information on CWD in Maryland and the DNR Response Plan, please visit the DNR Website at
Chronic wasting disease in a Wisconsin white-tailed deer farm
Delwyn P. Keane1, Daniel J. Barr, Philip N. Bochsler, S. Mark Hall, Thomas Gidlewski, Katherine I. O'Rourke, Terry R. Spraker and Michael D. Samuel Correspondence: 1Corresponding Author: Delwyn Keane, University of Wisconsin, Wisconsin Veterinary Diagnostic Laboratory, 445 Easterday Lane, Madison, WI 53706. mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000040/!x-usc:mailto:Delwyn.Keane@wvdl.wisc.edu
In September 2002, chronic wasting disease (CWD), a prion disorder of captive and wild cervids, was diagnosed in a white-tailed deer (Odocoileus virginianus) from a captive farm in Wisconsin. The facility was subsequently quarantined, and in January 2006 the remaining 76 deer were depopulated. Sixty animals (79%) were found to be positive by immunohistochemical staining for the abnormal prion protein (PrPCWD) in at least one tissue; the prevalence of positive staining was high even in young deer. Although none of the deer displayed clinical signs suggestive of CWD at depopulation, 49 deer had considerable accumulation of the abnormal prion in the medulla at the level of the obex. Extraneural accumulation of the abnormal protein was observed in 59 deer, with accumulation in the retropharyngeal lymph node in 58 of 59 (98%), in the tonsil in 56 of 59 (95%), and in the rectal mucosal lymphoid tissue in 48 of 58 (83%). The retina was positive in 4 deer, all with marked accumulation of prion in the obex. One deer was considered positive for PrPCWD in the brain but not in the extraneural tissue, a novel observation in white-tailed deer. The infection rate in captive deer was 20-fold higher than in wild deer. Although weakly related to infection rates in extraneural tissues, prion genotype was strongly linked to progression of prion accumulation in the obex. Antemortem testing by biopsy of recto–anal mucosal-associated lymphoid tissue (or other peripheral lymphoid tissue) may be a useful adjunct to tonsil biopsy for surveillance in captive herds at risk for CWD infection.
PLEASE NOTE 76 DEER WERE DEPOPULATED. SIXTY ANIMALS (79%) WERE FOUND TO BE POSITIVE BY IMMUNOHISTOCHEMICAL STAINING FOR THE ABNORMAL PRION PROTEIN (PrPCWD) IN AT LEAST ONE TISSUE; THE PREVALENCE OF POSITIVE STAINING WAS HIGH IN YOUNG DEER. ...TSS
Title: Chronic wasting disease in a Wisconsin captive white-tailed deer farm
Keane, Delwyn - U OF WIS, WIS VET DIAG LA Barr, Daniel - U OF WIS, WIS VET DIAG LA Bochsler, Philip - U OF WIS, WIS VET DIAG LA Hall, S - USDA, APHIS, VS, NVSL Gidlewski, Thomas - USDA, APHIS, VS O`rourke, Katherine Spraker, Terry - CO STATE UNIVERSITY Samuel, Michael - US GEOLOGIC SERVICE
Submitted to: Journal of Veterinary Diagnostic Investigation Publication Type: Peer Reviewed Journal Publication Acceptance Date: May 5, 2008 Publication Date: N/A
Chronic wasting disease is a fatal disease of deer and elk. Clinical signs, including weight loss, frequent urination, excessive thirst, and changes in behavior and gait, have been reported in mule deer and elk with this disorder. Clinical signs in captive white tailed deer are less well understood. In a previous study, a captive facility housed 200 deer, of which half were positive for the disease with no clinical signs reported. In this study, we examined 78 white tailed deer from a captive facility with a history of chronic wasting disease and no animals with clinical signs. Examination of the brain and lymph nodes demonstrated that the abnormal prion protein, a marker for disease, was observed in 60 of the deer. Biopsy of the rectal mucosa, a test that can be performed on live deer, detected 83% of the infected animals. The prion genetics of the deer was strongly linked to the rate of infection and to disease progression. The results demonstrate that clinical signs are a poor indicator of the disease in captive white tailed deer and that routine testing of live deer and comprehensive necropsy surveillance may be needed to identify infected herds. Technical Abstract: Chronic wasting disease CWD is a transmissible spongiform encephalopathy or prion disease of deer and elk in North America. All diseases in this family are characterized by long preclinical incubation periods following by a relatively short clinical course. Endpoint disease is characterized by extensive deposits of aggregates of the abnormal prion protein in the central nervous system,. In deer, the abnormal prion proteins accumulate in some peripheral lymphoid tissues early in disease and are therefore suitable for antemortem and preclinical postmortem diagnostics and for determining disease progression in infected deer. In this study, a herd of deer with previous CWD diagnoses was depopulated. No clinical suspects were identified at that time. Examination of the brain and nodes demonstrated that 79% of the deer were infected. Of the deer with abnormal prion in the peripheral lymphoid system, the retropharyngeal lymph node was the most reliable diagnostic tissue. Biopsy of the rectal mucosal tissue, a site readily sampled in the restrained or chemically immobilized deer, provided an accurate diagnosis in 83% of the infected deer. The retina in the eye of the deer was positive only in late stage cases. This study demonstrated that clinical signs are a poor indicator of disease, supports the use of the retropharyngeal lymph node as the most appropriate postmortem sample, and supports a further evaluation of the rectal mucosal tissue biopsy as an antemortem test on a herd basis.
A. ORAL TRANSMISSION to deer and elk is a very efficient mode for transmission. HIGH PROTEIN FEED will transmit CWD. high protein feed have been fed to deer and elk, especially in game farms.
B. COMMINGLING OF DISEASED ANIMALS AROUND BAIT PILE. chance of the environment in the surrounding areas becoming infected, from feces, urine, shedding, becoming a hot bed for animals to feed, congregate, and become exposed, and there is still very much the possibility of lateral transmission, especially with the CWD TSE, in deer and elk.
WHY ignore sound science ?
IT's the same with pouring a bottle of 100% deer urine scent formulas all over you and the environment, this is a proven mode of transmission. SO WHY DO IT?
leave your egos, and testosterone at the door, and look at the transmission studies, this is NOT rocket science. ...TSS
ENLARGING SPECTRUM OF PRION-LIKE DISEASES Prusiner Colby et al 2011 Prions
David W. Colby1,* and Stanley B. Prusiner1,2
+ Author Affiliations
1Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California 94143 2Department of Neurology, University of California, San Francisco, San Francisco, California 94143 Correspondence: email@example.com
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.
"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. ...
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
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 ProfessorDepartment of Chemical EngineeringUniversity of Delaware