Scientists are worried about the potential transmission of ‘chronic wasting disease in deer,’ commonly known as “zombie deer disease,” to humans.

Last month, the first case of chronic wasting disease (CWD) was discovered in Yellowstone National Park, sparking concerns among some scientists about the potential transmission of this fatal brain ailment to humans.

A deer carcass in the Wyoming region of the park tested positive for this highly contagious prion disease, known to induce weight loss, stumbling, listlessness, and neurological symptoms, as per the CDC. Chronic wasting disease has been identified in deer, elk, reindeer, and moose across North America, Canada, Norway, and South Korea.

The disease’s symptoms might take up to a year to manifest, leading some to nickname it “zombie deer disease” due to its impact on the hosts’ brains and nervous systems, resulting in drooling, lethargy, emaciation, stumbling, and a distinct “blank stare,” as reported by The Guardian. It’s fatal, with no known treatments or vaccines available.

Presently, scientists are cautioning about the potential transmission to humans, despite no documented cases thus far.

Epidemiologists emphasize that the absence of a “spillover” case doesn’t guarantee it won’t happen. CWD is part of a group of fatal neurological disorders, including Bovine Spongiform Encephalopathy (BSE), commonly known as “mad cow disease.”

Dr. Cory Anderson, from the Center for Infectious Disease Research and Policy (CIDRAP), drew parallels to the BSE outbreak in Britain, highlighting the unpredictable nature of spillover events from animals to humans. While there’s no certainty, preparedness is crucial, he emphasized.

Anderson also expressed concerns about the lack of effective eradication methods, both from infected animals and the contaminated environment. The pathogen’s resilience, persisting for years in soil or on surfaces, and its resistance to various disinfectants and extreme conditions like high temperatures and radiation, pose significant challenges.

Animal studies suggest a potential risk of CWD transmission to specific non-human primates, like monkeys, consuming infected animal meat or contacting brain or bodily fluids from affected deer or elk, according to the CDC. These findings raise concerns about a possible risk to humans, prompting global health recommendations to prevent prion diseases from entering the human food chain since 1997.

Reports indicate the disease’s spread in Wyoming since the mid-1980s, affecting a considerable portion of the mule deer population near Cody that migrates to Yellowstone’s southeastern area in summer. The long-term impact of the disease on the park’s deer, elk, and moose remains uncertain.

According to The Guardian, the Alliance for Public Wildlife estimated in 2017 that thousands of CWD-infected animals were consumed unwittingly by humans annually, with expectations of a 20% yearly increase in these numbers.