CWD UPDATE 63 September 19, 2005

Case Western University reports that they generated transgenic mice expressing the elk or human prion protein (PrP) in a PrP-null background. After intracerebral inoculation with elk CWD prion, two lines of “humanized” transgenic mice that are susceptible to human prions failed to develop the hallmarks of prion diseases after >657 and >756 days, respectively, whereas the “cervidized” transgenic mice became infected after 118-142 days. These data indicate that there is a substantial species barrier for transmission of elk CWD to humans.

Alberta has reported its first case of CWD in free-ranging deer. The positive was a mule deer found about 30 kilometers southeast of Oyen, Alberta. Alberta’s Sustainable Resource Development agency will increase surveillance in the vicinity of the confirmed case and enhance public awareness of CWD, especially among hunters and big game guides. A collection of about 50 deer in the immediate vicinity of the infected deer is being planned for September. This positive is very close to the Saskatchewan border, where CWD has been found previously.

The newest member of the CWD club in the United States is the great state of West Virginia. A road kill 2 ½ year old whitetail buck tested positive for CWD, as reported by the West Virginia DNR in early September. The animal was located in Hampshire County. Due to the uncertain ramifications that CWD may have on the white-tailed deer resource in West Virginia, the WVDNR is taking immediate action to gather more information on the prevalence and distribution of the disease in the area surrounding the known infected deer. This goal will be accomplished by increasing the number of deer tested with the help of other state and federal agencies, and local landowners.

Bovine Spongiform Encephalopathy (BSE) has been transmitted naturally between sheep for the 1st time a study at a U. K. experimental farm has shown. No evidence of BSE has emerged from testing sheep in abattoirs or on farms, although this did not begin until well after the BSE epidemic in cattle was in steep decline. Scientists from the government’s Veterinary Laboratories Agency have revealed that 2 ewes fed 5 milligrams of BSE-infected material had lambs that died of BSE after showing signs of infection in their tonsils 546 days after birth. Their mothers had shown no outward signs of the disease at lambing, one showing them 73 days after lambing, and the other 198 days after. But it is still not certain that the lambs were infected while in the uterus, or shortly before or after lambing. The lambs that seem to have inherited BSE showed a brain signature similar to BSE in cattle.

Indiana DNR Director Kyle Hupfer put the owners of the state’s hunting preserves on notice that killing animals, including white-tailed deer, behind tall fences is illegal and will be enforced starting next year. Hupfer also signed an emergency rule into law clarifying that it is illegal to hunt exotic mammals, such as elk and zebra. There are about 350 deer or elk farms in Indiana. Of those 225 have DNR-issued game breeder’s permits to breed and sell whitetail deer. The remaining 125 farms have elk and other exotic deer species. About a dozen offer hunting opportunities. Hupfer said Indiana law is clear that a game breeder’s license “does not allow the hunting or purposeful killing of animals maintained under that license.” A game preserve owner near Corydon, Indiana has sued the DNR over this ban, contending that the DNR ha exceeded its authority in announcing the ban. The lawsuit asks the court to declare the rule null and void.

The Minnesota DNR reports that all 13 elk that escaped from an elk farm in mid August have been collected and tested, with no positive results for CWD. Minnesota state law requires the DNR to kill any escapes if they are not recaptured within 24 hours. The DNR will continue to monitor the farm for additional escaped elk. Investigation indicates that these elk had been free-roaming off and on all summer.

The International Association of Fish and Wildlife Agencies has passed a resolution calling for the development of a National Fish and Wildlife Health Initiative under the leadership of the organization. The IAFWA Fish and Wildlife Health Committee will form a working group to develop the proposal and work with other interested agencies, organizations, and individuals to develop and implement the initiative. The guiding principals for this initiative, as submitted by the Health Committee, were also adopted at the annual meeting of the International.