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Real risk or irrational hype?



T His Winter was a bit quieter than usual for the folks at Silver Creek Specialty Meats in Oshkosh, Wisconsin. For generations winter has been, when hunters visit regularly to the low white brick buildings near the shores of Lake Winnebago, wearing the little things of the deer that she had killed last fall, so that it could be turned into wild sausages. However, this year no hunters came.

"It's not quite black and white, what are we going to do in the meantime?"

In August, Silver Creek sent Specialty Meats a letter informing customers that they would no longer accept game for processing , "As you probably know," the letter says, "the chronic wasting disease has widened steadily in the Wisconsin state wildlife population, and the disease has now been found in 19 counties across the state in wild deer due to the spread of the disease extremely difficult to sort out wild from CWD-infected areas. "

Deer with chronic wasting disease or CWD, tremble and drool. Often you can not hold your head. After all, they lose so much weight that they are little more than skin and bones. The disease is caused by a particular prion – one – protein infectious agent associated with various neurodegenerative diseases in mammals. And prion diseases are always deadly.

Although chronic wasting has not proven to be a risk to human health, its similarity to other prion diseases, including "mad cow disease" and Creutzfeldt-Jakob disease, which has symptoms similar to Alzheimer's disease, has been a cause for years concern. News from last summer about a running Canadian study in which two macaque monkeys matched the disease after drinking meat from a CWD-infected deer – the first time an animal evolved so close to people CWD – only aggravated that To care.



"That sealed the deal for us," says Katy Lehman, Silver Creek Specialty Meats, President of Operations. The letter soon went out.

And yet, a short drive from Wisconsin's CWD hotspot, another bakery sausage continues – like dozens of commercial game processors in the state – to make wild sausage brought out of the flesh by hunters. The butcher, who asked that his name and name of shop not be used for fear of losing business, is annoyed by Silver Creek Specialty Meats for stopping the processing of wild deer meat as it causes unnecessary anxiety and worry.

The media sensationalize the disease, he says, "every time there is a fright with a monkey."

The owner says that he and his staff are to be careful with care, including slaughter in a separate location reserved for deer meat only and that staff members do not touch the deer's brain or spine. This is more than enough to ensure safety, he said – not least because there is no evidence that chronic diseases pose a threat to humans.

It's a near-perfect encapsulation of the chronic wasting problem: two meat-processing companies less than 100 miles apart want only the best for their customers – and each one gets a very different assessment of CWD's risk revives.

Both say that science is the basis for their conclusion. And both are right.


T o date CWD has been detected in free-living deer, elk and elk in at least 24 states and two Canadian provinces, but it is not exactly a new disease. CWD was first discovered in 1966 in captivity Mule Deer in the Colorado Division of the Wildlife Foothills Wildlife Research Facility, but it would be years before it was understood what is now called a transmissible spongiform encephalopathy or TSE. At that time, these diseases, which made the brains spongy, were a mystery, and only three were known: scrapie, a sheep disease known for over 250 years; Creutzfeldt-Jakob, a disease of humans; and Kuru, also a disease of humans found only among the indigenous peoples of Papua New Guinea, who ate ritual human brains.

Scientists had already discovered that the infectious agent behind TSE could not be killed by boiling or exposure to acids, radiation, or antibiotics. But it was not until 1982 that Stanley Prusiner, an American medical researcher, discovered the prion and described it as the cause of TSE. (He later won the Nobel Prize for his work.)

Visual: Mark Hirsch / WireImage on Getty ">

▲ An employee of the Wisconsin Department of Natural Resources collects lymph node samples from a Whitetail Deer. [19659018] Visual: Mark Hirsch / WireImage on Getty

  • <a href = "https://undark.org/wp-content/uploads/sites/2/2018/04/elk2.jpg" data-lightbox = "post -image" data -title = " Visual: Tom Thorne and Beth Willilams Picture Gallery, Wildlife Disease Association ">

    Moose and elk are also susceptible to CWD, which can cause the animal to tremble and drool.

    Visual: Tom Thorne and Beth Willilams Photo Gallery, Wildlife Disease Association

  • <a href = "https://undark.org/wp-content/uploads/sites/2/2018/04/elk1.jpg" -lightbox = "post-image" data title = " Visual: Wyoming Game & Fish Department ">

    Often they can not hold their heads, and eventually they lose so much weight that they are little more than skin and bones.

    Visual: Wyoming Game & Fish Division

Then came the Insane Cow. BSE was identified in the United Kingdom in 1986. The British government initially claimed that beef madness was safe to eat, but more than 200 people across Europe would later die of it. The first case of BSE in humans, the variant of Creutzfeldt-Jakob disease, was diagnosed in 1996. This 10-year gap between the discovery of a disease in cows and the realization that, despite all the contrary assurances, it poses a threat to people who have eaten contaminated meat, is the cause of almost all worries about chronic wear and tear disease today.

While no one knows exactly how to transfer CWD from deer to deer, saliva is very suspect. Nasal mucus, urine and feces are also possible. His leaps over land and the world, however, are best explained by living animals that were transported as part of the captured deer and elk industry. These farms, commonly referred to as "deer farms" in the United States, are primarily captive-level hunting operations and their suppliers. Venison is mainly imported from New Zealand, which is CWD-free. Hunters who discard carcasses or parts in locations far from the kill site can also contribute to the spread of CWD, experts say.

The last fright with monkeys began last year. Stefanie Czub, a prion researcher based in Alberta, Canada and head of a reference laboratory for mad cow disease at the Canadian Food Inspection Agency and the World Organization for Animal Health, flew 2000 miles to Ottawa, Canada's capital, to deliver the results from her monkey research to representatives of various federal agencies personally. It was so important.

Her message was that five cynomolgus macaques had been given CWD in a year-long study in which 18 macaques had been infected with CWD in various ways. The results from three of the macaques would have been news enough: two had contracted CWD after their prions had been applied directly to their brains. That was new. And another macaque in Czub's study had gotten CWD after he had eaten brain tissue from an infected Whitetail Deer.

The World Health Organization, the CDC, Health Canada and numerous American states all recommend that no one eat the meat of prion-infected roe deer.

"The two remaining animals could be seen from a human health point of view, the most important," says Czub. They got meat from CWD-infected white-tailed deer that did not look sick. That was the kind of deer that any hunter could eat without a second thought. But at 5.4 and 6.2 years after the first feeding of this deer meat, the macaques previously classified as immune showed subtle symptoms. They were killed and CWD prions were found in their spinal cord.

The results were a surprise as a previous study found that this type of macaque appeared to be immune to a chronic wasting disease. After the flight to Ottawa, Czub presented the results at the Prion 2017 conference in Edinburgh, Scotland last May. Over the summer, more than 1,000 people, mostly federal veterinarians, have joined a webinar at the US Centers for Disease Control and Prevention, says Czub. She and her colleagues have not written any research yet, and while Czub says she intends to write these interim results, the study is only half way through. Ten of the original 21 animals (three are controls) are still alive.

Czub wants to keep the remaining macaques alive for as long as possible. She wants the disease to develop because it is known that prion diseases take years to show symptoms. It could also give her a better idea of ​​what the disease might look like in humans.

And yet, this kind of research is expensive – 7.9 million Canadians, so far, she says – and she's in the process of securing funding for another two years. In the meantime, the macaques in Germany are housed in one of the few institutions in the world that are certified to work with primates and prions. Because of the difficulty of working with primates and prions, Czub says, "This experiment will never be repeated."


The World Health Organization, the CDC, Health Canada, and the departments for health and natural resources in Wisconsin and other states including Minnesota, Colorado, Mississippi, Illinois, North Dakota and South Dakota are not waiting for further studies : Everyone recommends that nobody eat the meat of prions infected with prions.

Some hunters say these recommendations do not go far enough. "This is one of the most outrageous human susceptibility experiments in history," says Dave Clausen, a veteran veterinarian, former chairman of the Wisconsin Natural Resources Board and avid stag hunter.

Other hunters defy the recommendations – and sometimes this defiance has a scientific basis. "I harvested a moose several years ago, and the adult turned out to be positive for a chronic wasting disease," said Walt Cook, a clinical lecturer at Texas A & M University's College of Veterinary Medicine, at a Texas Parks hearing and Wildlife Commission. "Well, I ate it, that was my choice, and I do not think I look like I'm wasting, right?"

Later, Cook admitted that he would not give his wife or daughter meat from CWD-positive animals, and stated that he had worked with deer and elk in a CWD-infected area of ​​Wyoming for 23 years. The infected moose he knowingly ate, he said, is unlikely to be his first exposure to CWD, and he's confident in his chances. CWD is most similar to sheep scrapie, says Cook. "This disease [scrapie] has been around for hundreds, possibly thousands of years, literally millions of people have been exposed to scrapie without evidence of transmission." He also points to research showing that CWD prions just the wrong form for interacting with human prions.

  • </ a href = "https: // undark .org / wp-content / uploads / sites / 2/2018/04 / cwd_map_13.jpg" data lightbox = "post-image" data-title = " Visual: USGS ">

    By March 2018, at least 24 states and two Canadian provinces had reported cases of chronic cervical disease (CWD) in wild and captive animals.

Timothy Kurt did research at the University of California at San Diego. Kurt looked at the role of the 210 amino acids in the prion protein to find out why CWD is transmitted in some ways and not to others. He found that if one species had another amino acid at a key site, the diseased prion would not fit neatly into the healthy prion, like a zipper with teeth that do not match. This, Kurt believes, is the species barrier of CWD. The amino acid sequence differed between humans and deer at a key site. Another study showed that the amino acids of a macaque matched the wild sequence in the same place but not in humans.

There is such evidence that James Kroll, also known as "Dr. Deer" in the television show "North American Whitetail," to dismiss concerns about chronic waste disease as absurd. Kroll said he usually does not test where he hunts. "And why would I want it?" He asked. "I do not mind eating infected deer!" He adds that he is proud of the special report that his program on chronic wasting disease had in which his colleague ate CWD-infected meat in front of the camera.

Kroll has never studied CWD in the lab or on the field, but what he says matters more to hunters, especially in Wisconsin, and not just because he's on TV. In 2011, he was selected by Wisconsin Governor Scott Walker as Deer Trustee to direct the mess CWD had made from the stag herd of that state. Kroll believes that CWD is prevalent, "it has been out there for a long time" and that what appears to be an upswing in cases of CWD is simply an artifact for seeking it. "If you test it, you will find it," he says.

This, of course, ignores the opinions of colleagues studying CWD and states like New Jersey, Oregon, Maine, and California, who have been extensively testing for years of chronic wasting disease and have never had a positive outcome. It also ignores the states, such as Illinois and New York, where CWD has only been found in a small area, though deer have been tested throughout the state. And while Kroll argues that "CWD was a big cash cow for many states and scientists," federal funding for CWD research and monitoring in 2012 has even been reduced.

In November, two Wisconsin Congressmen instituted a bill to restore federal funding for monitoring and researching chronic wasting diseases. A similar law was presented by Senator Jon Tester, a Democrat representing Montana. The bills are still in the committee.


"F " onlying basic protocols to separate wild meat from other meat and to remove the central nervous system and dispose of it properly are the primary methods of addressing processing problems, "says Jeff Sindelar, an Associate Professor of Meat Science at the University of Wisconsin-Madison.

"There was never any association between eating wild and CWD," he says. "The risk is not zero, but it's pretty close to zero."

When consumers are concerned about the risk of CWD, these are social concerns, not science-based concerns. "There was never any connection between eating wild and CWD," he says. "The risk is not zero, but it's pretty close to zero."

Whether "pretty close to zero" is a consolation or a worry, of course, is a matter of perspective, and when asked, Sindelar said he does not give the processors any recommendations about removing the deer lymph nodes, though these are what Wisconsin Department of Natural Resources and others across the country test to diagnose the disease.

"There are lymph nodes throughout the body," says Sindelar. "It would be unreasonable to remove them all."

As it stands, hunters in Wisconsin do not have their deer examined for chronic wasting diseases, but many still do. (CWD testing is compulsory for all hunters killed deer in some areas of Michigan, Minnesota, Missouri, Texas, Virginia and Alberta, Canada.) All 50 states are doing some sort of CWD testing on wild deer, either random, volunteer or sick deer. ) In Wisconsin, if a killing test is positive, hunters can expect a phone call from state wildlife officials. If these hunters, like Kroll, say they intend to eat the meat anyway or share it with others, they will be asked to provide a list of names so that the State Ministry of Health can confirm who has consumed it. disease surveillance.

That's when some hunters just hang up, says Jim Kazmierczak, the animal health veterinarian for Wisconsin State. Some say they do not trust the government, says Kazmierczak. Some have other reasons not to attend. But many say so, and so far about 1,000 people in Wisconsin are helping the state to learn more about the potential dangers to human health caused by chronic wasteful diseases.


Share this story! Www.mjfriendship.de/de/index.php?op…=view&id=167 In Minnesota, it says that every hunter who said he or she would eat game meat from one Eating CWD – infected deer in her condition would get a phone call directly from her. "I would turn up at their homes if they did not want to talk to me," says Scheftel. "There is no evidence at this point that CWD has ever been transmitted to a person, but we still feel very strongly that humans should not eat meat from a prion-infected animal."

That certainly sounds overwhelming for some hunters who believe that with millions of people eating game meat every year, a human infection would have appeared in the 50 years since the discovery of CWD. Or that the CDC or other health researchers who were always on the alert would have attached a human prion disease cluster to CWD, if it had actually been the cause.

But feelings like that of Scheftel are enough for the team at Silver Creek Specialty Meats in Oshkosh. "Consumer safety is our biggest concern," it says in the company's August letter. "And no matter how small the risk (if any) of people who have been affected by the disease, we are not and will never be willing to make a profit for the safety and well-being of our customers."

Nevertheless, Katy Lehman allows Silver Creek's decision not to be the right one for everyone. "It's not all black and white," she says. Silver Creek considers the size of its processing plant, its location and product mix in its decision, Lehman notes, and these factors may add up differently for other companies. There is still no answer to whether CWD poses a risk to human health or not, says Lehman, the only question may be, "What are we going to do in the meantime?"


Madeline Bodin is a Vermont-based freelance author specializing in wildlife conservation. Her work has appeared in Scientific American, Popular Mechanics, National Wildlife and many other publications.


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