LARAMIE — Statewide surveillance to monitor chronic wasting disease (CWD) is finished, thanks to new testing procedures that allowed the Game and Fish Department to analyze more than twice the number of samples in half the time.
The ELISA (Enzyme-Linked Immuno Sorbent Assay) test, which certified in 2002, allowed G&F researchers, to analyze samples from 6,171 deer and elk before the new year. That compares to 2,550 samples analyzed by mid-March last year.
“In the past, we used to rely on the immunohistochemistry or IHC testing procedure, which was very time consuming,” says Hank Edwards, G&F disease specialist. “Whereas the new ELISA testing procedure has a much faster turnaround time, allowing us to analyze tissue samples in six weeks rather than six months. We have also switched from collecting the brain stem to collecting the retropharyngeal lymph nodes. Research has shown that early stages of CWD can be detected in these lymph nodes before it can be detected in the brain stem.”
Last spring, the G&F decided to conduct statewide surveillance during the 2003 big game hunting seasons to try to learn more about the distribution of the disease. That strategy was not impossible without the new test procedures and new equipment purchased through a federal grant.
“We learned a lot about the distribution of CWD in Wyoming during this expanded effort,” Edwards said. “In spite of the doubled workload only 156 animals tested positive, compared to the 115 positives last year, but we were able to document CWD in seven new hunt areas.”
The new hunt areas include 13 (Lusk), 41 (Worland), 70 (Shirley Basin), 74 (northwest of Laramie), 79 (Snowy Range), 81 (Sierra Madres) and 164 (Worland).
Hunter participation was key to the G&F’s efforts to monitor the prevalence and distribution of CWD. Testing was voluntary, but many hunters were more than willing to participate in the effort, in spite of the inconvenience. The G&F posted test results on their Web site and notified hunters by letter if their animal tested positive.
The World Health Organization says there is currently no evidence that CWD in deer and elk is transmitted to humans, but they further state no part or product of any animal with evidence of CWD or other transmissible spongiform encephalopathies, the name for that group of diseases, should be fed to any species – human, domestic or captive animal.
Although there is no evidence CWD is transmitted to humans, G&F is charged with managing the wildlife in the state, and officials want to continue to monitor the disease and its effects on wildlife.
Targeted surveillance also plays a role in monitoring CWD. Earlier this year targeted surveillance, taking animals that exhibit signs of CWD, revealed CWD in three new deer hunt areas 6, 8 and 80. The Department will continue with targeted surveillance efforts throughout the upcoming year.