Photo Credit: Kansas Department of Wildlife, Park adn Tourism
Chronic wasting disease, also known as "zombie deer disease," is a type of prion disease that infects cervids such as deer, elk, and moose. It is a neurodegenerative condition that spreads through direct and indirect contact with bodily fluids, waste, soil, water, and food. Although no cases have yet been reported in humans, recent cases of sporadic Creutzfeldt-Jakob disease (CJD) in hunters who ate meat from deer infected with CWD have raised questions about whether the disease can jump the species barrier.
CJD is a rare and fatal brain disorder that affects about one in every one million people worldwide. It is caused by the accumulation of an abnormal prion protein in the brain that destroys brain cells and causes neurological symptoms, such as dementia, personality changes, and movement disorders. CJD can be inherited or transmitted from exposure to infected tissues, such as contaminated surgical instruments or human growth hormone.
Variant CJD (vCJD), on the other hand, is a type of CJD that is caused by exposure to the prion protein that causes bovine spongiform encephalopathy (BSE), or "mad cow" disease. It was first discovered in the United Kingdom in 1996 and has been linked to the consumption of contaminated beef products. About 230 cases of vCJD have been reported globally, mostly in the UK.
The concern about CWD is whether it can also lead to a form of CJD in humans. The misfolded prion protein that causes CWD is similar to the one that causes CJD, but it is not yet clear whether it can infect humans. Some experts fear that as transmissions in animals increase across North America, Scandinavia, and South Korea, the risk of transmission to humans may also be increasing. However, the current evidence does not show that CWD can be spread to humans through eating meat, encountering infected wildlife, or drinking or touching contaminated soil or water.
The Centers for Disease Control and Prevention (CDC) advises people not to eat meat from deer and elk that look sick or test positive for CWD, to avoid handling or eating the brain, spinal cord, eyes, spleen, tonsils, and lymph nodes of deer and elk, and to have deer and elk meat tested for CWD before consuming it. The CDC also recommends hunters to wear gloves when field-dressing deer or elk, to minimize the handling of brain and spinal tissues, and to wash their hands and tools thoroughly afterward.
Increased surveillance and research are needed to establish whether CWD can cross over into humans and to develop effective strategies for preventing and controlling its spread. The nature of prions makes it challenging to detect and eliminate them, as they are resistant to heat, radiation, chemicals, and enzymes. Therefore, it is crucial to keep any prion disease out of the food chain and to minimize the exposure of humans and wildlife to contaminated materials.
CWD is a prion disease that infects cervids and can cause neurological symptoms and death. Although no cases have yet been reported in humans, the possibility of transmission from deer to humans remains a concern. The CDC recommends precautions to avoid exposure to CWD and to test deer and elk meat before consumption. Further research is needed to determine the risk of transmission to humans and to develop effective preventive measures.
