The discovery of Yellowstone National Park’s first case of chronic wasting disease (CWD) last month has raised concerns that the deadly brain disease may one day spread to humans, according to some scientists.
Deer carcasses in the Wyoming area of the park tested positive for the highly contagious prion disease that can also cause weight loss, stumbling, lethargy and neurological symptoms, according to the CDC.
It has been detected in deer, elk, deer and elk in areas of North America, Canada, Norway and South Korea.
Symptoms can take up to a year to develop and some have dubbed it “zombie deer disease” because it changes in the host’s brain and nervous system, leaving animals drooling, lethargic, emaciated, stumbling and with a distinct “blank stare”. according to the Guardian.
It is fatal, with no known treatment or vaccine.
And now scientists are sounding the alarm that it can infect humans, although no known cases have ever been recorded.
Epidemiologists say the absence of “overflow” cases does not mean it will not happen.
CWD is one of a group of fatal neurological disorders that includes Bovine spongiform encephalopathy (BSE), commonly referred to as “mad cow disease.”
“The BSE outbreak in Britain provides an example of how, overnight, things can go crazy when a spillover event occurs from, say, livestock to humans,” said Dr. Cory Anderson to The Guardian. Anderson is a program co-director at the Center for Infectious Disease Research and Policy (CIDRAP).
“We are talking about the potential for something similar to happen. “No one is saying it’s going to happen, but it’s important for people to be prepared,” Anderson added.
Yellowstone National Park saw its first case of chronic wasting disease (CWD) last month. Villagers Jim / SWNS
He added that what is also worrying is that there is no known way to eradicate it effectively and easily, “neither from the infected animal nor from the environment it has contaminated.”
Anderson said that once an environment becomes infected, the pathogen is very difficult to eradicate. It can last for years in dirt or on surfaces, and scientists report it is resistant to disinfection, formaldehyde, radiation and burning at 1,100 F, according to The Guardian.
The CDC says on its website that some animal studies suggest CWD poses a risk to certain types of nonhuman primates, such as monkeys, that eat meat from CWD-infected animals or come into contact with brain or body fluids from infected deer or elk.
“This study raises concerns that there may also be a risk to the public,” the CDC website says. “Since 1997, the World Health Organization has recommended that it is important to keep the agents of all known prion diseases from entering the human food chain.”
“The BSE outbreak in Britain provides an example of how, overnight, things can go crazy when a spillover event occurs from, say, livestock to humans,” said Dr. Cory Anderson to the Guardian. Reuters
Park officials say since the mid-1980s, the deadly brain disease has spread throughout Wyoming and is now found in most of the state. The disease is estimated to be found in 10-15% of mule deer near Cody that migrate to southeast Yellowstone in the summer. Yellowstone National Park said last month that the long-term effects of the disease on deer, elk and moose in Yellowstone are uncertain.
The Alliance for Public Wildlife, according to the Guardian, estimated in 2017 that 7,000 to 15,000 CWD-infected animals a year are unknowingly eaten by humans, and that number is expected to rise by 20% each year.
In 2005, researchers began observing 80 people who mistakenly ate infected meat and found that the group had “no significant change in health conditions,” according to USA Today.
Still, with hunting season underway, the CDC recommends that hunters “strongly consider testing the animal before consuming the meat.” The agency also advises hunters who harvest wild deer and elk from CWD-reported areas to check state wildlife and public health guides to see if animal testing is recommended or required in certain states or regions.
Meanwhile, Yellowstone staff have increased collaboration and information sharing with the Wyoming Game and Fish Department and other state agencies to identify areas within Yellowstone with increased CWD risk. Monitoring for the presence of CWD in deer, elk and stags in the park has also been enhanced as has testing of carcasses.
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Source: thtrangdai.edu.vn/en/
