Surveillance conducted by the S.C. Department of Natural Resources over the last four years continues to provide no evidence of chronic wasting disease in South Carolina.
Like fish and wildlife agencies in most states, the S.C. Department of Natural Resources (DNR) has been diligent in conducting surveillance for the disease in recent years. Sampling has been conducted in all counties, and more than 1,000 deer have been tested. The sampling methodology used by the DNR is designed to detect chronic wasting disease in the population, even if the prevalence was very low (less than 0.5 percent). Surveillance will continue this deer season and DNR’s goal is to sample an additional 500 deer stratified at the county level.
Chronic wasting disease is a transmissible spongiform encephalopathy that affects deer and elk, according to Charles Ruth, DNR Deer/Turkey Project leader. Although the disease has not been diagnosed in South Carolina, it has been found in 12 states and two Canadian provinces.
Transmissible spongiform encephalopathy diseases are fatal neurological diseases characterized by degeneration of the brain. Transmissible spongiform encephalopathy diseases that affect other animals include scrappie in sheep, bovine spongiform encephalopathy (commonly called “mad cow disease”) in cattle, and Creutzfeldt-Jakob disease in humans. There is no indication that chronic wasting disease of deer and elk can be transmitted between species other than cervids (deer family), and both the World Health Organization and federal Centers for Disease Control have indicated that there is currently no indication that the disease can infect humans.
“Chronic wasting disease attacks the central nervous system of the deer or elk and presents symptoms including extreme weight loss, excessive salivation and urination, odd behavior and poor coordination,” Ruth said. “The disease in deer or elk is infectious, communicable and always fatal. Chronic wasting disease has a prolonged incubation period (up to five years), and no current test exists to detect the disease in live animals. Diagnosis requires examination of the brain or lymph nodes.”
The chronic wasting disease agent is believed to be a prion, a mutated protein that causes normal proteins in the body to fold abnormally, which causes sponge-like holes in the brain. It is not known exactly how chronic wasting disease is spread, but it is believed that the agent may be spread both by direct animal-to-animal contact and indirectly by contact with a previously contaminated surface like the soil. Chronic wasting disease has been diagnosed in Colorado, Illinois, Kansas, Nebraska, New Mexico, New York, South Dakota, Utah, West Virginia, Wisconsin, Wyoming, and the Canadian provinces of Alberta and Saskatchewan.
South Carolina should continue to have low risk of having a problem with chronic wasting disease for two reasons, Ruth said. First, South Carolina is geographically far from any known chronic wasting disease. Second, there is evidence that movements of deer/elk for commercial purposes may have played a role in the current chronic wasting disease situation, and DNR has historically had a closed-door policy on importation of cervids for commercial purposes like deer farming or ranching. DNR plans to continue chronic wasting disease surveillance at some level for the foreseeable future, according to Ruth. “There is simply too much at stake not to make every effort to protect the state’s white-tailed deer resource and the deer hunting tradition,” Ruth said. “Not only are white-tailed deer the designated state game animal, but the economics associated with deer hunting in South Carolina are very important with more than $200 million in annual retail sales being generated at the local level.”