Primates developed Chronic Wasting Disease after consuming tainted meat in an experiment, giving heft to Wyoming Game and Fish Department advice to test game meat from suspect hunt areas.
The experiment led by the Canadian Food Inspection Agency resulted in transmission of CWD from cervid (moose, deer and elk) meat to primates — cynomolgus macaques monkeys. The monkeys were infected by both an injection into the brain and by CWD-infected muscle fed into the stomach via a tube.
The findings suggest that primates could potentially contract the fatal disease simply by eating meat from infected animals. It was previously suspected transmission could only occur through handling or consuming tainted brain tissue.
There’s no known transmission of CWD from cervids to humans, the agency Health Canada said. However, a transmission path is now possible, according to preliminary findings that have not been peer-reviewed.
“These findings suggest that CWD, under specific experimental conditions, has the potential to cross the human species barrier, including by enteral (intestinal) feeding of CWD infected muscle,” Health Canada reported.
CWD, caused by a misshaped protein called a prion, is similar to mad cow disease (BSE) and the human cousin, Creutzfeldt–Jakob disease. All cause degeneration of neurological tissue and systems, among other fatal problems.
What does Wyoming do?
Some big game hunting seasons are underway in Wyoming, and the WGFD continues to offer free CWD testing of animals along with expedited testing for $30.
“We’ve had quite a discussion about this in light of the new research,” Wyoming’s Chief Game Warden Brian Nesvik told WyoFile on Tuesday. “We recommend folks test their animal in those areas where we know CWD has been found.”
Maps of CWD-positive areas for various species are available on the Game and Fish website.
“If somebody tests an animal [and it’s positive] we just recommend folks don’t eat that meat,” Nesvik said. “We stuck with that.”
The recommendation is consistent with guidelines from the Centers for Disease Control and World Health Organization, he said.
Health Canada said that despite the news of the experiment and its advisory, it was not changing its warnings about CWD. That warning recommends “avoiding consumption of foods from known infected or any diseased animals and taking precautions when handling cervid carcasses.”
Further, Health Canada says warnings “should be provided to groups who may be expected to have higher exposure to cervids through hunting and diet (e.g. rural and Indigenous populations).”
Wyoming Game and Fish also recommends hunters not kill animals that appear to be infected with CWD. There’s no known cure for the family of diseases, and all are ultimately fatal.
“Up front we ask people not to harvest those animal that look sick,” Nesvik said. Infected animals appear listless, skinny, can have drooping ears, can drool, and wander in circles.
But behavioral observations are no guarantee of the status of an animal, he said. “The majority of CWD-positive animals that are harvested appear completely normal.”
Hunters who kill an animal must abide by game laws that require the retrieval and preservation of edible parts, regardless of the animal’s appearance. Hunters must have proof of infection — the results of a test — before they can discard meat. “They would need to have some kind of a confirmation [that] something was wrong with the animal,” Nesvik said.
Game and Fish enforces a number of regulations regarding the transport of animal parts from positive areas, all of which can be found on the department’s website. Among the rules are that the brain and spinal column not be moved from areas where CWD is known to exist.
Did you learn from this story? Support WyoFile through Old Bill’s Fun Run
In the U.S. in 2007 nearly two thirds of those surveyed said they had eaten venison or elk meat, according to the CDC. “If CWD could spread to people, it would most likely be through eating of infected deer and elk,” the agency says. “Strongly consider having the deer or elk tested for CWD before you eat the meat.”
WHO says “no tissue that is likely to contain the BSE [Bovine Spongiform Encephalopathy] agent, nor part or product of any animal which has shown signs of a TSE [Transmissible Spongiform Encephalopathy] should enter the (human or animal) food chain.” That means infected meat or animal parts should not be fed to livestock.
When the conversation about CWD pivots to just the hunting aspect , as it seems to here and everywhere that Wyoming Game and Fish broaches the problem , it’s a little bit disingenuous to pivot away from the nonhunting public health concerns at the same time.
Be that as it may , G & F is scared. The 7-ton Wooly Mammoth in the room is the behavorial drawdown that hunting diseased animals has on Game & Fish revenues. The 2016 annual report shows that of the total $ 75 million operating budget of Wyo G&F , $ 30 million came from hunting and fishing licenses… forty percent. But total expenses for maintenance and operation of the entire Department budget was $ 60 million.
The day it’s reported in the national media that a Wyoming hunter got an incurable fatal disease from a deer, elk , or moose will be the day Wyo G&F has a paralyzing stroke. Same story in all the other states where CWD is prevalent, but Wyoming currently has the highest prevalence of CWD. The prions are marching on the feedgrounds and Yellowstone.
Here is a real world analogue: there is a Brucellosis problem in my Park County. It’s a ” hot spot” for the dreaded disease , thanks to migratory Elk from Yellowstone spending the winter and calving in Park County before heading back to summer range. Along the way , they apparently transmit brucellosis to pastured cattle , and the Park County stockgrowers go to DefCon2. They want all the migratory Elk killed, but that thankfully is not as realistic an option as it is in Montana next door ( the Bison debacle).
What Wyo G&F did instead a few years back was extend the Elk hunting season past the end of the year all the way to February 1 for cow Elk in a couple B. abortus hot spots hunt areas. Licenses were available for next to no money , or no charge at all, for taking one or two cow elk. The thinking was by late November the Yellowstone and Thorofare elk had migrated in , and that was the time to harvest cows and nip the Brucellum in the womb. So we had a winter elk hunt.
– except nobody cared to hunt diseased elk in sub-zero weather , no matter how hungry they were or how much room was left in the chest freezer. The elk herds in the Cody hunt area are actually increasing in population , in spite of wolves and grizzlies and diseases. We still have an abundance of Mule Deer , unlike other regions of Wyoming. So many inf act that 300 live inside the Cody city limits yearround. City of Cody officers put night vision scopes on AR-15 rifles and shot 50 doe deer inside the city limits of Cody this past winter. Every one of those deer was tested for CWD by G&F. Two of them flunked. So CWD is here , in my neighborhood actually.
The same Brucellosis that causes cattle to abort their calves is known as Undulant Fever when it afflicts humans , and can be fatal. Back before pasteurization of dairy products became the law in the middle 20th century , over 11,000 people died of Undulant Fever in the American Midwest states. But you cannot pasteurize a prion away . In f act, I don’t even think short of cremation that you can cook it to death. It’s almost indestructible, and an Unknown.
We’ve all seen the near-panic caused by a single instance of Mad Cow in the UK and Alberta. What that 7-ton Wooly Mammoth in the Game and Fish public meeting room is obscuring is the fact that we don’t know very much about the deformed proteins called Prions that cause BSE and CWD and Kreutzfeld-Jakob. We do know those prions can survive for decades or even centuries in moist clay soil , but know almost nothing about the patholgy they inflict or its transmission vector. It exists at root level of RNA-DNA biology .
Alarming stuff if you are zootic patholigist. Positively terrifying if you are a Wyoming Game and Fish administrator.
G&F has been soft-pedalling this for years. Left unsaid is the fact that many infected animals are unknowingly taken to processors, who cut up the animals using bone saws, mix meat from different animals for burger and sausage and generally cross-contaminate everything they process. Field-dressing the animals also presents a risk, and that is always done well before testing.
G&F has a built-in conflict of interest on all this; their funding comes from license fees and warning about CWD (which, by the way, G&F introduced at the Sybille research station) will cut into licenses.
Living in the eastern part of the state, I quit hunting deer and elk years ago for just this reason.
Here in Alberta it is mandatory to have your animal tested if harvested from areas know to have the problem. The testing is done at no cost and there are stations with freezers all over the place.
One more time, as I said when prions were first injected into the brain of an animal to get infection – how fast do the infected animal and the animal receiving prions directly into the brain have to be running for transmission of CWD to occur this way? It is impossible to transmit CWD this way! Second, was this meat put into monkey stomachs cooked? If not, the whole test was bullshit!
Your average BBQ or kitchen stove many not provide enough heat to kill pirons. “Prions can be destroyed through incineration providing the incinerator can maintain a temperature of 900 F for four hours.” http://www.bseinfo.org/deactivationofprions.aspx
Cooking meat to that temp may make it tough, well actually ashes.
Not true. Cooking at regular temperatures does not denature (inactivate) prion proteins. I agree with your first statement, however.
they’re going to have to come up with a home testing kit or people will just stop hunting
If the Wyoming Game and Fish Department is concerned about CWD you would never know it from looking at their printed hunting regulations. The regulations suggest hunters not eat an animal that looks obviously ill, but they don’t tell hunters that all animals from the CWD endemic area should be tested for CWD. The WGFD website has some good information, but not all hunters have access to the internet.
Hunting season is beginning, but I haven’t seen any press releases warning of the risks the new research suggests hunters face.
Wyoming has the highest rates of CWD in the wild anywhere in the world, so we should be doing a better job of warning people. Lives could be at stake.