CHRONIC WASTING DISEASE UPDATE November 12, 2002
Chronic Wasting Disease has been confirmed in a young female white-tail deer from near the town of Roscoe in Winnebago County, Illinois. The animal was shot because it exhibited the clinical signs of CWD and tests run by the NVSL were positive for CWD. This location is just a few miles from the Wisconsin border. The Illinois DNR plans to collect up to 3,500 deer for sampling during the upcoming fall deer season.
A sixth deer farm in Wisconsin has been placed under quarantine since trace-backs from a positive farm involve this latest addition to the quarantined farms. Farms have now been quarantined in Marathon County (1), Portage County (2), Walworth County (2) and Dane County (1). The positive farms were in Walworth and Portage Counties.
The Mayo Clinic of Minnesota has examined all 158 cases of Creutzfeldt-Jakob disease it had recorded between 1976-1996 to determine if there may be any connection to other TSE diseases. Looking for anything atypical, and especially anything that looked like Mad Cow disease, they found nothing unusual with the CJD cases that would indicate a connection to any other TSE.
The U. S. Department of Health and Human Services has proposed funding studies to determine the transmissibility of scrapie and CWD to humans. Secretary Tommy Thompson announced the awarding of grants, totaling approximately 29 million dollars to several Universities and labs to conduct the studies. The National Institute of Health and the Harvard Medical School will look into the possibility of transmission to humans. Colorado State University will be studying the transmission of CWD from deer to deer and look at the possibility of developing a vaccine for CWD, and Chase Western University will be studying the effects of CWD on transgenic mice.
The Texas Parks and Wildlife Commission has lifted their ban on the import of white-tail deer into that state. In addition to lifting the import ban, the commission approved a process for testing for CWD in deer herds prior to granting a Trap, Transport and Transplant (Triple T) Permit for moving deer within the state. Applicants will be required to have test results from a number of deer that would be an equivalent to 10 percent of the number of deer to be trapped, and the number must be between 10-40 deer that show no positive tests for CWD before the state agency will consider issuing a Triple T permit. Permittees will also be required to permanently tattoo all moved deer with an identification number, and deer temporarily relocated for nursing or veterinary purposes may not leave the state for those purposes.
The Oregon Fish and Wildlife Commission has permanently banned the import of cervids into that state. This permanent ban replaces a temporary ban put in place in August. The ban also includes all exotic deer species such as fallow, sika and axis deer. Reindeer are exempted from the ruling. Also exempted are cervids for approved research purposes.
A joint Legislative Committee in Wisconsin has extended the ban on feeding and baiting deer in that state until April 1, 2003. If not extended, the ban would have ended on November 20, in the middle of the Wisconsin deer season. The rule extension also permits the DNR to continue to hold extended deer seasons to combat CWD. The legislature will consider a permanent ban on baiting and feeding early next year when they meet in regular session.
More positive deer are being found in northwest Colorado as their deer and elk season continues. The latest findings are in areas around Craig, Meeker, Pagoda and Green Mountain Reservoir. Hunters have now submitted more than 8,000 animals for testing and tests have been completed on more than 6,500 of those. CWD has been detected in 50 animals, including 16 outside the area of northeastern Colorado where CWD has been detected for more than two decades.
The Center for Veterinary Biologics has certified a ELISA based test for CWD in mule deer developed by Bio-Rad laboratories of Hercules, California. This is the first commercial test kit for CWD approved by the CVB. The company is working with several diagnostic laboratories and state wildlife agencies to obtain the data to get the test kit approved for white-tail deer also. The ELISA based test can produce results in a short time frame (1 week or less) and will provide a quicker turnaround time than the IHC test. All animals showing positive results on the ELISA test will be confirmed with an IHC test.
The New Zealand Ministry of Agriculture and Forestry has dedicated approximately $1 million to the study of scrapie and CWD in that country. Although neither disease has been found in New Zealand, increased surveillance is necessary to achieve international requirements for disease free status. New Zealand has never had a case of CWD but has been exposed to the risk of the disease through the importation of elk from Canadian herds subsequently found to hold positive animals.