November 7, 2007
Surveillance conducted by the S.C. Department of Natural Resources over the
last 5 years continues to provide no evidence of Chronic Wasting Disease in
South Carolina. Like fish and game agencies in most states, DNR has been
diligent in conducting surveillance for the disease in recent years.
Sampling has been conducted in all counties and over 1,500 deer have been
tested. The sampling methodology used by the department is designed to
detect CWD in the population, even if the prevalence was very low (less
than 0.5%). 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 or CWD is a Transmissible Spongiform Encephalopathy
(TSE) that affects deer and elk, according to Charles Ruth, Deer/Turkey
Project leader for the S.C. Department of Natural Resources (DNR). Although
the disease has not been diagnosed in South Carolina, it has been found in
14 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, 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. CWD has been diagnosed in Colorado, Illinois, Kansas,
Minnesota, Montana, Nebraska, New Mexico, New York, Oklahoma, 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
CWD for two reasons, Ruth said. First, South Carolina is 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
of cervids for commercial purposes like deer farming or ranching.
DNR plans to continue CWD 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."
DNR protects and manages South Carolina’s natural resources by making wise
and balanced decisions for the benefit of the state’s natural resources and
its people.
|