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“Zombie deer disease” spreads in the United States. What is it?

A crazy carbon-like infection disease that can make the brain of deer, moose and elk into "Swiss cheese" spreads in at least 24 states – and some experts warn that it could eventually enter humans. Known as Chronic Wasting Disease – and is often called "zombie deer disease" – the lethal progressive neurodegenerative disease was first identified in the 1960s. Like crazy cows, chronic wasting disease spreads by prions, the zombie-like pathogenic proteins that do not live and cannot be killed. When they infect an animal, they eat in the brain, causing a cascade of symptoms similar to dementia and eventually leading to death. While the disease is still rare, scientists believe it is more prevalent than ever because of how humans act deer and other ungulates. "What we have seen over the past few decades is that it slowly spreads in the wilderness deer populations," says Peter Larsen, assistant professor of veterinary science at the University of Minnesota who has studied the pathogen. It also spreads among prisoners, moose and reindeer that are transported around the country and abroad to hunt ranches, petting zoos and Christmas farms. That's how the disease ended up in South Korea, Larsen said. (It has also been identified in Canada and Norway.) When new outbreaks begin, they are almost impossible to contain because, unlike viruses and bacteria, prions cannot be killed and there is currently no good way to find them. Scientists have long wondered if the disease, like crazy cow, can make hope…

A crazy carbon-like infection disease that can make the brain of deer, moose and elk into “Swiss cheese” spreads in at least 24 states – and some experts warn that it could eventually enter humans.

Known as Chronic Wasting Disease – and is often called “zombie deer disease” – the lethal progressive neurodegenerative disease was first identified in the 1960s. Like crazy cows, chronic wasting disease spreads by prions, the zombie-like pathogenic proteins that do not live and cannot be killed. When they infect an animal, they eat in the brain, causing a cascade of symptoms similar to dementia and eventually leading to death. While the disease is still rare, scientists believe it is more prevalent than ever because of how humans act deer and other ungulates.

“What we have seen over the past few decades is that it slowly spreads in the wilderness deer populations,” says Peter Larsen, assistant professor of veterinary science at the University of Minnesota who has studied the pathogen. It also spreads among prisoners, moose and reindeer that are transported around the country and abroad to hunt ranches, petting zoos and Christmas farms. That’s how the disease ended up in South Korea, Larsen said. (It has also been identified in Canada and Norway.)

When new outbreaks begin, they are almost impossible to contain because, unlike viruses and bacteria, prions cannot be killed and there is currently no good way to find them.

Scientists have long wondered if the disease, like crazy cow, can make hope for humans. (Mad cow in people is known as Creutzfeldt-Jakob’s disease.) At the end of last summer, we received a preliminary and frightening response. In a newspaper published in the journal Emerging Infectious Diseases researchers from Scotland and Canada through an experiment in a petri dish showed that diseased animal prions can actually infect human cells.

Since then, there has been no direct evidence of human disease. Yet, it exerted research Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, to compare chronic wasting disease to mad cow recently. Osterholm, it turns out, also warned the British government about the risks of mad cows before hundreds of people were infected in the UK and around the world in the late 1

990s. Sitting before a state commission in Minnesota on February 7, he called the chances that people were infected with chronic wasting disease “likely” and “possible” and added: “The number of human cases will be essential and not isolated events”. [19659007] According to Larsen, it is not time to freak out – but he warned that this is a growing public health threat. People should not consume infected meat, he said, noting that there is actually no good way to know if meat is infected. “There is currently no opportunity for people to quickly test for prions in meat, on meat processing surfaces or in live deer,” he said. “The reason is that we must act now to develop new technologies to detect and destroy prions.”

Let’s go through what we know about this emerging infectious disease.

1) What is “zombie deer disease”?

Officially called chronic wasting disease, zombie deer disease is a lethal progressive neurodegenerative disease believed to affect deer, elk, reindeer and elk. It was discovered in cultivated deer in Colorado in the 1960s, and it has been exciting scientists ever since.

The disease is caused by prions – which are not viruses or bacteria. Prions are almost indestructible pathogenic proteins that trigger cells, especially in the brain and spinal cord, to fold abnormally and begin to sob. When that happens, the infected animals begin to develop a series of terrible symptoms – dementia, hallucinations and difficulty walking, talking and eating. The animals eventually become wobbly and disoriented. These symptoms worsen over time, and since there is no cure, they always lead to death. “[This] is a neurodegenerative disease – not a zombie disease in Hollywood”.

The reason why the disease got its official name – chronic wasting disease – is that when prions take over an animal, it begins to lose weight and waste it. The prions “turn the brain into Swiss cheese,” says Larsen.

But Larsen called “zombie deer disease” an unfortunate and potentially misleading moniker. “I’ve only seen a deer that has died of [chronic wasting disease] and it was emaciated,” he said. “There are no zombie-like symptoms. Instead, the symptoms are what you expect to see in a very sick animal: thin, weak and unable to function normally.” It is important to remember that [this] is a neurodegenerative disease – not a zombie disease in Hollywood. “

2) How does it spread in animals?

An animal with chronic wasting disease can spread prions to other animals by direct or indirect contact with body fluids such as faeces, saliva, blood or urine. means that the disease can be spread if an infected deer is injured, for example, and its blood touches an uninfected animal, or if a healthy animal contacts soil, food or water contaminated by a sick deer.

It is not everything, Larsen said. Because the prions are so robust, they can survive in environments – farms, forests – this year, decades even. “So let’s say you have a deer with chronic wasting disease, and it started to throw [prions] in the urine, the stool, the saliva. “If the deer dies on the forest floor, the prions can survive and bind to the ground, where plants wet them up. These plants can then spread prions through their leaves, Larsen said.

“So it spreads in the wild, slowly. And every year we see more and more cases of chronic wasting disease.”

3) How would it spread to humans?

There have been no documented cases of chronic wasting disease in humans – but researchers believe that this is possible and becomes more likely, since infections become more common in animals.

So far, the only evidence researchers have spread to other animals indirectly. In laboratory experiments, researchers have shown that the disease can be spread in squirrels and mice bearing human genes, the Centers for Disease Control and Prevention says. In an yet published study, spouses – a primate species that is genetically similar to humans – who were born infected meat, retreated into the disease.

“Experiments are performed [also] where researchers take environmental samples, such as stones or pieces of wood, that have prions on them,” says Larsen. “They then place these contaminated objects in cages with transgenic hamsters and the hamsters develop the disease.”

Finally, in another recently published study, researchers found that chronic wasting disease prion infected human cells in a petri dish

The CDC says these experiments “cause concern that [chronic wasting disease] may pose a risk to humans and suggests that it is important to prevent human exposure to [the disease] “. The most likely way this can happen is if a person, like a hunter, eats contaminated meat

It leads us to another troubled fact about chronic wasting disease: “With a prion you can’t [cook it off]. The temperatures needed to destroy it is far beyond what you can cook, says Larsen.

The only way to make prions is non-infectious is to use lye, a strong alkaline solution that drastically changes pH balance and autoclaves or presses them – at 270 degrees Fahrenheit, “Most do not have access to this approach,” says Larsen, and “the point is that it is difficult to handle [infectious] prions in the environment because we do not know exactly where they are lurking.” That brings us to the next problem with this disease.

4) Where is zombie deer disease in the United States?

Well, we only know was chronic wasting disease was . Deer can only be diagnosed after they have died ( research They need to access tissues that are deep in animal brain and to test them. But animals can carry the pathogens for years and not show any signs or symptoms. “The deer could go on a 40-mile journey, strolling [infected] prions in feces or urine,” says Larsen. “If we go and say this is a [chronic wasting] deer at this point on the map, what you don’t see on that map is everywhere that deer has been in the last two years.”

As of January 2019, 251 counties in 24 states had reported chronic wasting disease in free deer, the CDC reported. You can see them here:


Chronic wasting disease in free deer, reported by the United States counties, from January 2019. CDC

But scientists think the spreading area is much wider. The CDC has also noted that some states have better animal disease monitoring systems than others, so the current map may be more a reflection of where the discovery is strongest (and earlier disease) than where the lethal prions are currently spreading in the United States.

5) Can we stop the disease from spreading?

Since there is no way to eradicate and cure the disease right now, scientists recommend that states where it is known to disseminate attempts to contain it by identifying sick animals.

Now, there is another problem: The tools available to do so right now are very limited. The diagnosis of detecting the disease in animals is not always accurate, not all states have access to them, and again they can only confirm the presence of the infection in an animal after it is already dead. It can also take days or weeks to get results. This means that the disease can be moving for a while before someone knows it is there.

Therefore, Jeremy Schefers, a veterinarian of the University of Minnesota, recently arrived lawmakers in his research finance state to develop better diagnostic tools and help researchers answer basic chronic wasting disease issues. Here are Schefers talking to the Minnesota Post:

We have to find infected animals before their death, but we have no test. … We need to know how other animals move CWD prion around the environment, but we have no test for it.

We need to know if the local butcher shop is polluted and can be cleaned efficiently, but we do not have a test for it. We need to know if prions move from the soil to plants and possibly are infectious, but we have no test for it. … I want to know how much it is in the earth and I want to know how much it takes to infect something, but we have no test for it.

All hunters need access to a test that can easily be bought and quickly discovered CWD in the deer before being cut into 100 pieces and fed to their family. These hunters do not have access to a test.

6) How can people protect animals and themselves?

Health personnel are most concerned about the possibilities for hunters to be exposed to the disease through animals carrying prions. So, anyone who is hunting in areas where chronic wasting disease is known to spread should take the following precautions, according to the CDC:

  • No shot, handling or eating elk or deer that looks unhealthy or “seems weird”.
  • In field dressings (or removing organs of) a hunting animal, wearing latex or rubber gloves, avoid touching the animal’s organs – especially the brain and spinal cord tissues – and avoid using tools that are also used at home.
  • Get deer or elk meat tested for prion disease before eating the meat. But the CDC also warns that because diagnostic tools for the disease are still limited, “A negative test result does not guarantee that an individual animal is not infected” with chronic wasting disease, although it “may reduce the risk of exposure”. [19659046] When the meat is treated commercially, ask the butcher if they handle and process several animals at once (to avoid cross-contamination).

So how about consumers of game meat, like game and the restaurants that serve it? Therefore, Larsen did not have a comforting answer.

He advised that anyone who eats game meat or a restaurant serving games asks about where the meat came from. And restaurants should ensure that their meat is free of the disease. But in practice, it is not easy because of how long it takes to get results from diagnostic tests.

“If you are a hunter and shoot a deer to feed your family or sell, wait two weeks [for a test result]?” Larsen asked. “How do you keep the meat fresh?”

So while consumers may have the right to know if their meat has been infected with the pathogenic prions, there is currently no effective way to get answers.

“People have interacted with deer for centuries,” says Larsen, “for food, sports or simply looking at them in nature.” But that tradition is “under attack now because of this pathogen”.

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