EAST LANSING, Mich. — Michigan’s Chronic Wasting Disease Symposium began with researchers, wildlife managers and others with a vested interest in CWD meeting to learn more about the origin and transmission of CWD, the risks it poses to deer, moose and elk populations, and how to best manage the fatal neurological disease in the wild.
The symposium opened with a presentation from Dr. John Fischer, head of the Southeastern Cooperative Wildlife Disease Study at the University of Georgia. Fischer outlined what we know, and don’t know, about CWD over five decades of research.
Chronic wasting disease is a worldwide phenomenon. Currently 22 states and two Canadian provinces have identified CWD in captive and/or free-ranging cervids (deer, moose, elk). South Korea officials have identified CWD in imported elk, and Norway officials have confirmed CWD in wild reindeer.
Believed to be caused by prions, which are corrupt proteins. It’s unclear how CWD first began, although researchers speculate that scrapie found in sheep and goats morphed into CWD. Researchers have also documented CWD transmission between captive and free-ranging animals, prompting concerns that CWD may be transmitted to free-ranging, healthy deer from infected captive populations.
Officials believe management of CWD must be sustained and involve surveillance and monitoring. Efforts in Illinois to control CWD showed some evidence that sustained culling of animals in CWD areas will slow the progression of the disease. Many states have found higher CWD-prevalence rates in mature bucks and roadkill animals, prompting some states to collect more tissue samples from those groups.
Finally, why should states struggle to manage CWD? Because CWD-positive deer herds will not thrive, and it’s best to minimize exposure of CWD to humans. Although it is believed that humans cannot get CWD, researchers have found cross-species transmission (more on this later).