The rate of chronic wasting disease (CWD) is on the rise among deer in Iowa County, Wisconsin and elsewhere across the state. CWD is a fatal, transmissible spongiform encephalopathy (TSE) similar to what is commonly known as mad cow disease that is caused by twisted proteins, or prions. For hunters, writes outdoors reporter Patrick Durkin, this means the disease might be affecting the herd now. For anyone who eats venison, this means greater chances that the disease could conceivably make the species jump and infect humans, according to Dave Clausen, a veterinarian whose term on Wisconsin’s Natural Resources Board expired in May.
About one out of every three male deer aged 2.5 years and older carries CWD in north-central Iowa County, as does one out of every six yearling male deer (1.5 years old), according to the
Wisconsin State Journal, and the rates are climbing at about ten percent a year. As several experts told Durkin, the increasing rates are “unprecedented,” “frightening,” and “disturbing.”
Over 633,000 hunters purchased licenses to hunt white-tailed deer in Wisconsin in 2012, according to the Department of Natural Resources (DNR). The primary deer hunting season (for guns) runs for nine days in late November. An exact number of Wisconsinites who eat hunted venison is not known, although media reports indicate it is large. But testing of these deer for CWD is on the decline, even as infection rates rise. In 2002, over 40,000 deer were tested in Wisconsin, and .51 percent tested positive. In 2012, 6,611 deer were tested, and 5.13 percent tested positive.
As then-Natural Resources Board member Clausen wrote in a white paper on CWD and human health in 2012, the “ever-increasing number of CWD infected deer on the landscape . . . and the accompanying exponential increase of environmental contamination with CWD prion will result in increased inter-species, including human, exposure to the CWD prion . . . . Under our current management strategy[,] human exposure is and will increase.”