Chronic Wasting Disease (CWD) is a significant concern for wildlife populations across North America. As this fatal neurological condition spreads among deer, elk, and moose, questions arise regarding its potential implications for human health. This article explains CWD, assesses its risk to humans, and outlines precautions for those interacting with affected animals or consuming venison.
Understanding Chronic Wasting Disease
Chronic Wasting Disease is a transmissible, fatal neurological disease primarily affecting cervids, including deer, elk, moose, and reindeer. It is caused by prions, abnormal, misfolded proteins that induce normal proteins in the brain and nervous system to also misfold. The accumulation of these misfolded proteins leads to progressive damage within the brain, creating a spongy appearance.
Infected animals gradually exhibit signs such as drastic weight loss (wasting), along with behavioral changes like stumbling, lack of coordination, excessive drooling, and increased thirst and urination. They may also show a lack of fear of humans. The disease has a prolonged incubation period, with symptoms typically appearing months to years after initial exposure. CWD prions can spread directly through contact between animals or indirectly via environmental contamination from bodily fluids like saliva, urine, and feces, and can persist in soil for years.
Assessing Human Risk
No confirmed cases of Chronic Wasting Disease exist in humans. Public health agencies, including the Centers for Disease Control and Prevention (CDC), continue to monitor the situation closely, acknowledging that the possibility of transmission to humans remains a theoretical concern. A “species barrier” in prion diseases suggests that differences in protein structures between species can make cross-species transmission challenging.
However, the precedent set by Bovine Spongiform Encephalopathy (BSE), or “mad cow disease,” which transmitted to humans, prompts ongoing vigilance. Research efforts are underway to better understand this potential risk. Some experimental studies involving non-human primates have shown CWD transmission through infected meat or brain tissues, even from asymptomatic animals. Conversely, human cerebral organoid studies indicated a strong species barrier. Despite these varying experimental outcomes, prions are not destroyed by cooking and can have long incubation periods, leading public health agencies to recommend precautions.
Precautions for Hunters and Consumers
Given ongoing research and prion disease characteristics, public health and wildlife agencies advise specific precautions for hunters and venison consumers. Hunters should avoid shooting, handling, or consuming sick or dead animals. Wear latex or rubber gloves when field dressing or butchering harvested animals.
Minimize handling high-risk tissues like the brain, spinal cord, eyes, spleen, tonsils, and lymph nodes, as they harbor higher prion concentrations. Dispose of these tissues properly, ideally in approved landfills inaccessible to other animals. Many states offer CWD testing for harvested animals; hunters should check local guidelines. If an animal tests positive, do not consume the meat. Use dedicated knives and cutting boards for wild game, separate from kitchen utensils, and clean tools thoroughly with a 50/50 bleach solution to minimize exposure.