The discovery of Yellowstone National Park's first chronic wasting disease (CWD) last month has raised concerns that the deadly brain disease could one day spread to humans, according to some scientists.
According to the CDC, a deer carcass in the Wyoming section of the park tested positive for the highly contagious prion disease, which can cause weight loss, clumsiness, lack of attention and neurological symptoms.
It has been found in deer, elk, reindeer, and moose in parts of North America, Canada, Norway, and South Korea.
It can take up to a year for symptoms to appear, and some have called it “zombie deer disease” because it changes the hosts' brains and nervous systems, leaving the animals drooling, lethargic, emaciated, limp and “blank-eyed,” according to the Guardian.
With no known treatments or vaccines, it is fatal.
Although no known case has been recorded so far, scientists are now warning that it may affect humans.
Epidemiologists say that won't happen because there hasn't been a “spillover” case yet.
CWD is a group of fatal neurological disorders that includes bovine spongiform encephalopathy (BSE), commonly referred to as “mad cow disease.”
“The BSE outbreak in Britain provided an example of how crazy it can get overnight when there's a spillover from livestock to people,” Dr Cory Anderson told The Guardian. Anderson is Program Associate Director at the Center for Infectious Disease Research and Policy (CIDRAP).
“We're talking about the possibility of something similar happening. Nobody's saying it's definitely going to happen, but it's important for people to be prepared,” Anderson added.
And what's more worrying is that there is no way to effectively and easily eradicate it, “neither from animals nor from the environment it pollutes.”
Andersen said that once an infection occurs in the environment, it is very difficult to eradicate the pathogen. It can last for years on dirt or surfaces, and it's resistant to disinfectants, formaldehyde, radiation and burning at 1,100 F, scientists report, according to The Guardian.
The CDC says on its website that some animal studies suggest that CWD poses a risk to certain types of nonhuman animals, such as monkeys that eat meat from animals infected with CWD or come in contact with brain or body fluids from infected deer or mice.
“These studies raise concern that people may be at risk,” the CDC website says. “Since 1997, the World Health Organization has recommended that it is important to prevent all known agents of prion diseases from entering the human food chain.”
Since the mid-1980s, the deadly brain disease has spread across Wyoming and is now found in most parts of the state, park officials said. The disease is estimated to occur in 10-15% of mule deer Close to Rs Migrates southeast of Yellowstone in summer. Yellowstone National Park said last month that the disease's long-term effect on deer, elk and moose in Yellowstone is uncertain.
The Alliance for Public Wildlife, according to the Guardian, estimated in 2017 that between 7,000 and 15,000 CWD-infected animals are unknowingly eaten by humans a year, and this number is expected to increase by 20% annually.
In 2005, researchers began monitoring 80 people who had mistakenly eaten the tainted meat and found “no significant changes in health” in that group, USA Today reported.
Still, during hunting season, the CDC recommends that hunters “inspect those animals before consuming the meat.” The agency advises hunters who harvest wild deer and mice from areas with CWD to check state wildlife and public health guidance to see if animal testing is recommended or required in a given state or region.
Meanwhile, Yellowstone staff have increased cooperation and information sharing with the Wyoming Game and Fish Department and other state agencies. Surveillance for CWD in deer, elk and moose in the park has also been intensified, including testing from carcasses.
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