Chronic Wasting Disease (CWD) is a neurological disorder that impacts members of the deer family, known as cervids, including white-tailed deer, elk, and moose. The disease has been detected in wild and farmed populations across North America and in other countries. Since millions of people consume venison annually, the presence of CWD raises serious public health questions about the safety of consuming meat from potentially infected animals. Current scientific understanding suggests a theoretical risk, prompting health agencies to issue strong precautionary advisories.
The Nature of Chronic Wasting Disease
Chronic Wasting Disease belongs to a group of fatal neurological disorders called Transmissible Spongiform Encephalopathies (TSEs), which also includes “mad cow disease” in cattle. The causative agent is not a virus or bacterium but an abnormally folded protein known as a prion. These misfolded prions induce normal, healthy proteins in the host to also change shape, leading to their accumulation in the brain and nervous tissue.
The accumulation of these resistant proteins creates microscopic holes in the brain tissue, giving it a sponge-like appearance. Prions are remarkably resilient, showing resistance to standard sterilization methods, including cooking temperatures that typically destroy pathogens. This durability is a primary reason for concern regarding food safety.
Infected cervids often undergo a long incubation period, which can last for years, before clinical signs become noticeable. The disease is characterized by progressive weight loss, or “wasting,” along with behavioral changes such as listlessness, excessive salivation, and poor coordination. While these signs are clear indicators of advanced disease, an animal can be contagious and test positive for CWD long before it appears sick.
Current Scientific Assessment of Human Risk
Public health agencies currently state that no confirmed cases of CWD infection have been reported in people. Historically, a “species barrier” has been believed to protect humans from CWD transmission, a defense that failed in the case of bovine spongiform encephalopathy (BSE) crossing to humans as variant Creutzfeldt-Jakob Disease (vCJD). The theoretical risk to humans remains a serious concern, particularly because CWD is highly infectious among cervids and the prions are so environmentally persistent.
Experimental studies using non-human primates, such as squirrel monkeys, have shown that CWD can be transmitted to them through the consumption of infected meat or brain tissue. These findings demonstrate that the species barrier is not absolute and that cross-species transmission is biologically possible under certain conditions. This evidence is a key factor driving the precautionary advice from health organizations.
A 2024 case report highlighted two deer hunters who developed Creutzfeldt-Jakob Disease (CJD) after consuming venison from a CWD-endemic area. While CJD occurs naturally, the cluster of cases in people exposed to the same deer population is suggestive of a possible novel animal-to-human transmission. This finding has intensified the call for further investigation into the potential risks associated with consuming CWD-infected deer.
Due to the persistent theoretical risk and the inability to destroy prions through cooking, organizations like the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) advise against consuming meat from any animal known to be infected with CWD. This precautionary stance prioritizes public safety. Epidemiological studies continue to monitor human populations, particularly those with higher exposure, to look for any correlation between CWD and human prion diseases.
Necessary Precautions for Hunters and Consumers
The most effective step hunters can take to protect themselves and their families is to have harvested animals tested for CWD, especially when hunting in known endemic areas. Hunters should contact their state or provincial wildlife agencies to find out about mandatory or recommended testing protocols and locations for sample submission. It is strongly advised not to consume any meat from the animal until a negative test result has been confirmed.
Hunters should never shoot, handle, or consume any cervid that appears sick, is acting abnormally, or shows signs of advanced wasting. When field dressing a carcass, individuals should wear latex or rubber gloves and minimize the handling of high-risk tissues. These high-risk tissues are where prions concentrate most heavily:
- Brain
- Spinal cord
- Eyes
- Spleen
- Tonsils
- Lymph nodes
To avoid cross-contamination during processing, hunters should “bone out” the meat. This means separating the muscle tissue from the bone without using a saw on the backbone or skull. Boning out the meat naturally removes most high-risk tissues, and cutting away all fat and connective tissue will remove any remaining lymph nodes. If commercially processing, ask the butcher to process your animal individually to ensure your meat is not mixed with that from other animals.
All tools, equipment, and work surfaces used for processing must be thoroughly cleaned with soap and water, followed by disinfection using a bleach solution. Carcass parts and processing waste should be disposed of properly according to local regulations, ideally leaving high-risk tissues at the kill site to minimize environmental contamination outside the endemic area. Following these safety protocols significantly reduces the potential for human exposure to the CWD prion.