Proceedings of the Vertebrate Pest Conference

Chronic Wasting Disease (CWD) was first described in captive mule deer in a Colorado research facility in 1967 and subsequently classified as a transmissible spongiform encephalopathy in 1978. The first detection of CWD in a free-ranging population was in Colorado elk in 1981. During the 1990s, CWD was identified in free-ranging mule deer, white-tailed deer, and elk in Colorado and Wyoming. By 2000, CWD was considered a disease affecting free-ranging and captive cervids, with a limited distribution in several western states and western provinces in Canada. Following the outbreak of Bovine Spongiform Encephalopathy in Great Britain during the 1980s and resulting variant Creutzfeldt-Jakob disease in humans in the 1990s, CWD began to garner more attention. Surveillance for CWD increased in both captive and free-ranging cervids, and the disease was subsequently identified in numerous additional locations. Currently, CWD has been detected in either free-ranging or captive deer and elk in 14 states and 2 Canadian provinces. Most recently (2005), the disease was detected in free-ranging deer in New York, West Virginia, Kansas, and Alberta and in captive herds in New York. Across most of the geographic range where CWD has been detected, disease prevalence remains low. However, the disease has continued to spread from the initial foci where it was detected and continued to increase in prevalence. Management efforts to contain or eradicate CWD have not yet been successful, and in some local areas the disease has reached disconcerting levels.