The group consensus was that a mandatory control program needed to be enacted with official tests and movement criteria. To date in South Dakota, there have been three elk herds with confirmed CWD and five others that were exposed to the affected herds. The latter have been quarantined for from one to five years. A surveillance program of free-ranging wildlife has been developed that includes examination of deer and elk killed by hunters. CWD is a spongiform encephalopathy believed to be caused by one or more cervid- specific prion strains that differ from all other animal and human prion strains studied to date.
Transmission can occur between species.
CWD, which has been recognized as a syndrome in deer for 30 years, occurs in free-ranging deer and elk in limited portions of southeastern Wyoming and north central Colorado. Clinical signs include loss of body condition, behavioral changes, excessive salivation, and occasionally, incoordination and tremors. The origin of CWD is not known but its relationship to other transmissible spongiform encephalopathies indicates it is not bovine spongiform encephalopathy or a previous characterized strain of scrapie. Dr. Kathleen O'Rourke with the U.S. Department of Agriculture's Agricultural Research Service, who has developed a live animal test for scrapie in sheep, indicated that she was working on a similar live animal test for CWD in cervids. The committee called on wildlife agencies to continue or start surveillance for CWD in wild cervid populations.