Thanks to a federal grant and the cooperation of hunters, landowners, and deer processors, the S.C. Department of Natural Resources recently completed the most in-depth surveillance effort for Chronic Wasting Disease in South Carolina with no evidence of the disease detected.
Sampling was conducted in all South Carolina counties and the findings, from more than 500 total deer; give natural resources officials, hunters, and other deer enthusiasts reason to believe that South Carolina may avoid this potentially devastating disease.
Chronic Wasting Disease or CWD is a Transmissible Spongiform Encephalopathy (TSE) that affects deer and elk, according to Charles Ruth, Deer Project leader for the S.C. Department of Natural Resources (DNR). Although the disease has not been diagnosed in South Carolina or any other Southeastern state, it has been found in 12 states and two Canadian provinces. TSE’s are fatal neurological diseases characterized by degeneration of the brain. TSE’s that affect other animals include scrappie in sheep, bovine spongiform encephalopathy (commonly called “mad cow disease”) in cattle, and Creutzfeld-Jakob disease in humans. There is no indication that CWD 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.
“CWD 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. CWD 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 CWD agent is believed to be a prion, which is 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 CWD 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.
Since 1998, DNR has coordinated with the Southeast Cooperative Wildlife Disease Study, which is part of the University of Georgia’s School of Veterinary Medicine, to conduct surveillance for CWD in South Carolina. This surveillance includes diagnostic analysis of target or profile animals that exhibit CWD-like symptoms. In 2003, thanks in part to a grant available to all states through the U.S Department of Agriculture, DNR’s surveillance effort was increased to include active surveillance where samples are taken from otherwise healthy hunter-killed deer sampled at deer processors or hunting clubs.
Normally, all deer-related research and management in South Carolina is supported solely by funds associated with hunters’ participation in DNR’s antlerless deer tag programs. The availability of the grant through the U.S. Department of Agriculture has been important in several respects, according to Ruth. First, although it has not covered all of the costs associated with CWD surveillance in South Carolina, the grant has greatly offset the costs to DNR, which is important considering the state budget problems the last few years. Second, it has allowed an increased sampling effort. Third, the federal governments’ involvement in the CWD issue demonstrates that the disease is a problem of national significance.
South Carolina should have minimal risk of having a problem with CWD for two reasons, Ruth said. First, the closest area with diagnosed CWD is northern Illinois and southern Wisconsin, placing South Carolina geographically far from any known CWD. Second, there is evidence that movements of deer/elk for commercial purposes may have played a role in the current CWD situation, and DNR has historically had a closed-door policy on importation for commercial purposes like deer farming or ranching.
Although personnel numbers are down and financial resources are at a premium, DNR plans to continue CWD surveillance 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 over $200 million in annual retail sales being generated at the local level.”
For more information, call the DNR Columbia office at (803) 734-3886.