The recent discovery of chronic wasting disease (CWD) in Yellowstone National Park has sparked concerns among scientists about the potential transmission of this fatal brain disease to humans.
Last month, a deer carcass in the Wyoming section of the park tested positive for CWD, a highly contagious prion disease affecting deer, elk, reindeer, and moose. Known symptoms include weight loss, stumbling, listlessness, and neurological issues, leading some to colloquially label it the “zombie deer disease.” CWD has been identified in North America, Canada, Norway, and South Korea.
CWD’s impact on hosts’ brains and nervous systems manifests in animals displaying drooling, lethargy, emaciation, stumbling, and a distinctive “blank stare.” This invariably fatal disease lacks known treatments or vaccines and can take up to a year for symptoms to surface.
Scientists are now sounding the alarm that CWD might potentially jump to humans, although no such cases have been documented to date. Epidemiologists caution that the absence of a “spillover” case doesn’t guarantee immunity, drawing parallels to other fatal neurological disorders like mad cow disease (Bovine spongiform encephalopathy or BSE).
Dr. Cory Anderson, program co-director at the Center for Infectious Disease Research and Policy (CIDRAP), points to the BSE outbreak in Britain as an example of how swiftly a spillover event can escalate. While he emphasizes that it’s not certain to happen, preparedness is crucial.
The concern deepens as CWD presents challenges in eradication. Once the environment is contaminated, the pathogen is highly resilient, persisting for years in soil or on surfaces. It shows resistance to disinfectants, formaldehyde, radiation, and incineration at 1,100°F.
The Centers for Disease Control and Prevention (CDC) notes on its website that animal studies suggest CWD may pose a risk to certain non-human primates. The CDC advises testing animals before consumption, especially in regions with reported CWD.
Yellowstone National Park, where CWD was recently discovered, has seen the disease spread across Wyoming since the mid-1980s. The long-term impact on deer, elk, and moose within the park remains uncertain.
The Alliance for Public Wildlife estimated in 2017 that 7,000 to 15,000 CWD-infected animals are consumed unwittingly by humans annually, with an expected annual increase of 20%. Although a 2005 study on individuals who inadvertently consumed infected meat showed no significant health changes, vigilance and testing remain key, especially during hunting seasons.
Yellowstone officials are intensifying collaboration with the Wyoming Game and Fish Department and other agencies to identify high-risk areas within the park. Increased monitoring and testing of carcasses aim to better understand and mitigate the threat of CWD.
How is the CWD outbreak changing your hunting plans this year? Leave your thoughts in the comments below.