Chronic Wasting Disease was first recognized as a clinical "wasting" syndrome in 1967 in mule deer in a wildlife research facility in Northern Colorado. It was identified as a Transmissible Spongiform Encephalopathy (TSE) in 1978. In 1981, CWD was detected in a wild elk and in 1985 it was detected in a wild mule deer in Colorado. Further surveillance showed the disease was present in wild deer and elk in northeastern Colorado and southeastern Wyoming. For many years CWD in wildlife was thought to only occur in this region, referred to as the "CWD endemic area." However, wildlife surveillance begun in earnest in 1997 by wildlife agencies led to detection of CWD outside of the historic endemic area. APHIS provided assistance to the wildlife agencies for much of this surveillance.
From 2002-2011, APHIS supported surveillance in wild, free-ranging deer and elk providing CWD testing for an average of 90,000 samples collected yearly on a nationwide basis. By January 2012, CWD had been identified in free-ranging, wild deer, elk, and moose in multiple states to include: Colorado, Illinois, Kansas, Maryland, Minnesota, Missouri, Nebraska, New Mexico, New York, North Dakota, South Dakota, Utah, Virginia, West Virginia, Wisconsin, and Wyoming. View a map depicting states with CWD in the free-ranging cervid populations.
CWD was detected in a farmed elk herd in South Dakota in 1997. Since then, additional positive farmed elk and deer herds have been identified in other states to include: Colorado, Kansas, Michigan, Minnesota, Missouri, Montana, Nebraska, New York, Oklahoma, and Wisconsin. View a map depicting states with CWD in farmed/captive cervid herds.