Scientists fear that a nearly 100 percent deadly “zombie deer disease” may be evolving to infect humans.
Chronic wasting disease, as it is also known, is a contagious neurological condition that kills virtually all animals it infects and is spreading rapidly among deer populations across the United States.
The disease is caused by misfolded proteins, when proteins do not fold into the correct shape, called prions. After infection, prions travel throughout the central nervous system and leave prion deposits in brain tissues and organs.
Recent studies have shown that prions have the ability to infect and multiply in human cells under laboratory conditions, which has raised the possibility of spillover.
It is believed that humans can contract the disease by eating infected venison or by contact with contaminated soil and water.
At least 32 states in the United States and parts of Canada have received reports of a virus called “zombie deer disease” that could potentially be transmitted to humans.
In the photo, a biologist removes lymph nodes from deer to test them for chronic wasting disease.
Investigation suggest that it is possible that prions attached to elements of the environment could cause the properties of the prions to change, including their degree of infection and their potential to infect other animal species or even humans.
It can take more than a year for an infected animal to develop symptoms, which can include drastic weight loss, stumbling, and listlessness.
It is known as “zombie deer disease” because it causes parts of the brain to slowly degenerate to a spongy consistency and the animals drool and stare before dying. There are no treatments or vaccines.
The exact route of transmission is not fully understood, but it is believed to be transmitted from animal to animal by eating forage or water contaminated with infected feces or by exposure to carcasses.
Direct contact, including saliva, blood, urine, and even antler velvet during the annual molt, can also contribute to the transmission of the pathogen.
Any deer that dies on a farm should be tested for a chronic wasting disease. Because the disease is so contagious, if one animal tests positive, the entire herd is considered infected.
The disease is believed to only infect animals such as deer, moose, reindeer, caribou and moose.
It can take more than a year for an infected animal to develop symptoms
In 2023, a group of 68 researchers from around the world began analyzing what would happen if a human spill occurred.
Michael Osterholm, an infectious disease expert at the University of Minnesota and a leading authority on chronic debilitating diseases, told KFF Health News: ‘The take-home message is that we are not prepared.
‘If we saw an overflow right now, we would be in free fall. There are no contingency plans for what to do or how to follow up.’
The team is preparing for a possible outbreak, examining laboratory capacity, diagnostics, surveillance, education and outreach.
While it is thought that transmission could occur when humans eat infected meat, humans are already exposed to infected deer through hunting and consumption.
In recent years, people have eaten tens of thousands of infected animals and there have been no known cases of the disease in humans.
Reports indicate that between 7,000 and 15,000 infected animals were eaten in 2017, and the number is expected to increase by 20 percent annually.
It is almost impossible to get rid of as it survives intense heat and disinfectants.
The environmental persistence of the disease means that humans can also be exposed through contaminated soil and water.
In September 2022, researchers at the University of Calgary published the first study showing that “the barrier to chronic wasting disease prions infecting humans is not absolute and that there is a real risk that they could be transmitted to humans.” humans”.
Prion disease attacks proteins in the brain, causing them to clump together before death.
Dr. Sabine Gilch, associate professor and Canada Research Chair in Prion Diseases at the University of Calgary, said: “Mad cow disease [also known as bovine spongiform encephalopathy (BSE)] We know that prion diseases can jump the transmission barrier from animals to humans.
“During the BSE crisis, BSE was transmitted to humans through contaminated meat or food products and caused a new form of human prion disease, called variant Creutzfeldt-Jakob disease.”
Chronic washing disease can infect more areas of an animal’s body than other prion diseases such as mad cow, meaning it could be more likely to be transmitted to people who eat venison.
Osterholm and his team recently received more than $1.5 million in funding to study the possibility of chronic wasting disease passing to humans or domestic animals.
Because deer are so important to indigenous people, numerous Minnesota tribal groups are collaborating with experts to generate ideas on how to control the disease.
Chronic wasting disease was initially discovered in 1967 in Colorado in captive deer, but has now been found in animals in at least 31 states, four Canadian provinces and four other foreign countries.
Other prion diseases include mad cow disease, which has killed more than 200 humans, according to the FDA.
Mad cow disease infected humans through consumption of contaminated beef.