According to media reports, a case of "zombie deer disease (CWD)" was discovered in Yellowstone National Park in the United States last month, sparking concerns among scientists that there is a risk of the disease spreading to humans in the future. A deer carcass in Yellowstone National Park tested positive for a highly contagious prion, according to the U.S. Centers for Disease Control and Prevention (CDC). The disease is a prion disease that affects deer, elk, reindeer, sika deer and moose, causing weight loss, staggering gait, lethargy and other neurological symptoms.
It is worth noting that this is not the first time this disease has been identified. In the past few years, the virus has been found in deer, elk, reindeer and moose in the United States, Canada, Norway and South Korea.
It is reported that symptoms of infection can take up to a year to appear, and some call it "zombie deer disease" because it changes the host's brain and nervous system, making the animals drool, lethargic, thin, staggering, and have "blank eyes." The disease is fatal to animals and there is currently no treatment or vaccine to prevent it.
Now, scientists are sounding the alarm that it could infect humans, although no known cases have been recorded.
Epidemiologists say just because "spillover" cases haven't occurred yet doesn't mean it won't happen. Zombie deer disease is one of a group of fatal neurological diseases that includes bovine spongiform encephalopathy (BSE), commonly known as "mad cow disease." "The BSE outbreak in the UK provides an example of how things can go crazy overnight when a virus jumps from livestock to humans."
Equally concerning, scientists note, is the fact that there is currently no known way to effectively and easily eradicate the virus, either from animals infected by it or from environments contaminated by it. The virus can persist in soil or surfaces for years, and scientists report that it is resistant to disinfectants, formaldehyde, radiation and incineration.
The CDC said on its website that some animal studies suggest that zombie deer disease poses a risk to certain types of nonhuman primates, such as monkeys, if they eat the meat of infected animals or are exposed to the brain or body fluids of infected deer or elk.
"These studies raise concerns that humans may also be at risk," the CDC said. "Since 1997, the World Health Organization has recommended that it is important to prevent agents of all known prion diseases from entering the human food chain."
According to 2017 data from the American Federation of Public Wildlife, 7,000 to 15,000 animals infected with zombie deer disease are unknowingly eaten by humans every year, and this number is expected to grow at an annual rate of 20%.