Millions of hunters travel into the forests and grasslands of North America each autumn in order to harvest deer. People devour the sausage, burgers and steaks produced from venison throughout the winter.
But these hunters are doing more than just upholding an American custom. Researchers studying infectious diseases claim that they are also at the forefront of a condition called chronic wasting disease, which poses a major risk to public health.
Misfolded proteins known as prions are the source of the neurological disease, which is contagious, rapidly progressing, and always fatal. As of right now, only cervids (elk, deer, reindeer, caribou, and moose) are known to be infected.
Scientists studying animal diseases are concerned about the quick spread of CWD in deer. Recent studies suggest that the disease-causing prions may be changing to become more capable of infecting people and that the barrier to a spillover into humans may not be as strong as previously thought.
Growing response to the Chronic Wasting Disease
There is a growing response to the threat. In 2023, a group of scientists started “working on a major initiative, bringing together 68 different global experts on various aspects of CWD to really look at what are the challenges ahead should we see a spillover into humans and food production,” according to Michael Osterholm, a leading authority on Chronic Wasting Disease and an infectious disease expert at the University of Minnesota.
“Our lack of preparation is the key takeaway,” stated Osterholm. “We would be in free fall right now if we had a spillover. There are no backup plans for what to do or how to investigate further.”
With an emphasis on public health surveillance, lab capacity, prion disease diagnostics, livestock and wildlife surveillance, risk communication, and education and outreach, the team of experts is preparing for a potential outbreak.
There have been tens of thousands of infected animals consumed by humans in recent years, raising concerns, yet no documented human cases of the disease exist.
Many hunters have debated whether or not to treat the possibility of Chronic Wasting Disease seriously. “The general belief I come across is that no one has contracted this illness,” stated writer and MeatEater founder Steve Rinella, whose media and lifestyle business centres around hunting and preparing wild animals.
“I am not going to worry about it because it hasn’t jumped the species barrier,” they believe, according to Rinella. “That would change dramatically if a hunter got CWD.”
Other prion illnesses that have afflicted people include Creutzfeldt-Jakob disease and bovine spongiform encephalopathy, popularly known as mad cow disease. More than 200 individuals died from mad cow, primarily in France and the United Kingdom. According to some scientists, Alzheimer’s and Parkinson’s disease may also be brought on by
Since its discovery in 1967 in confined deer in Colorado, CWD has spread extensively. Animals from at least thirty-two states, four provinces in Canada, and four other international nations have been reported to have it. It was discovered in Yellowstone National Park for the first time recently.
Prions are nearly impossible to remove and behave extremely differently from bacteria and viruses. The director of the Chronic Wasting Disease Alliance, Matthew Dunfee, stated that specialists refer to it as a “disease from outer space.”
The signs are scary. The brain degenerates into a porous substance. The illness, which is also referred to as “zombie deer disease,” causes affected animals to stagger, slobber, and stare vacantly until they pass away. There’s no vaccination or therapy for it. It also resists autoclaving, or medical sterilisation, making it very difficult to eliminate with chemicals or high heat.
As Osterholm noted, cooking does not eliminate prions. Regretfully, he stated, “the prions are concentrated when cooking. According to him, it increases the likelihood that people will eat them.
Despite the fact that CWD has not been linked to domestic animals or humans, researchers are extremely worried about these possibilities, which Osterholm’s group has now been awarded over $1.5 million to investigate. If Chronic Wasting Disease can infect humans, it may spread to venison consumers more readily than other prion illnesses like mad cow since it may infect more body parts in animals.
According to research, every year between 7,000 and 15,000 diseased animals are unintentionally eaten by hunter families; this figure rises as the disease spreads throughout the continent. Although it is possible to test wild game for CWD, doing so is difficult and not often done.
Its extended latency makes establishing if Chronic Wasting Disease has impacted humans a significant challenge. It can take years for a person who ingests prions to develop the ensuing illness, so there might not be a clear link between eating deer and getting sick.
In the environment, prions are incredibly persistent. They can even be absorbed by plants and stay in the ground for many years.
Prevention focuses on the rapid testing of deer and other cervid carcasses because eating venison is the most likely pathway for spillover. Currently, a hunter can drive a deer to a check station, where a sample of the lymph nodes is submitted to a laboratory. Most hunters choose not to do it because findings may not be received for up to a week.
For instance, deer hunting is well-known in Montana. Since its initial discovery in the wild there in 2017, Chronic Wasting Disease has expanded throughout a large portion of the state. The lack of concern Montana wildlife authorities have observed among hunters is in spite of warnings and free testing. According to Brian Wakeling, head of the Montana Department of Fish, Wildlife & Parks’ game management bureau, “we have not seen a decrease in deer hunting because of this.” In 2022, hunters in Montana killed around 88,000 deer. There were only 5,941 samples collected, and 253 of them had positive tests.
According to experts, a quick test would significantly boost the quantity of animals examined and aid in preventing spillover.
Given the significance of deer to Native Americans, a number of Minnesotan tribal nations are collaborating with University of Minnesota specialists to develop strategies for disease surveillance and control. White Earth Nation tribal biologist Doug McArthur stated in a statement announcing the programme that “the threat and potential for the spread of CWD on any of our three reservations has the ability to negatively impact Ojibwe culture and traditions of deer hunting providing venison for our membership.” (The Red Lake Band of Chippewa and the Leech Lake Band of Ojibwe are the other groups mentioned.)
Its extended latency makes establishing if Chronic Wasting Disease has impacted humans a significant challenge. It can take years for a person who ingests prions to develop the ensuing illness, so there might not be a clear link between eating deer and getting sick.
Peter Larsen is co-director of the Minnesota Centre for Prion Research and Outreach in addition to being an assistant professor in the University of Minnesota’s College of Veterinary Medicine. The centre was established in an effort to anticipate potential spillover by researching many facets of prions. “Our mission is to learn everything we can about not just Chronic Wasting Disease but other prionlike diseases, including Parkinson’s and Alzheimer’s disease,” he stated. According to him, “we are studying the biology and ecology” of the misfolded protein. “How do prions travel across their surroundings? How can we reduce danger and enhance the welfare and health of animals?”
New technologies to speed up and simplify testing are part of that objective. Although it can take weeks to receive findings, researchers have created a method for hunters to conduct their own testing. It is hoped that a test that cuts the wait time to three or four hours would be available within the next two years.
“With all the doom and gloom around Chronic Wasting Disease, we have real solutions that can help us fight this disease in new ways,” Larsen stated. “There’s some optimism.”
