A new case of a disease called ‘zombie deer disease’ has raised concerns that the disease could spread to humans in what scientists say could be a ‘slow-moving disaster’.
Chronic Wasting Disease (CWD), which causes animals to drool, listlessly, stumble and look with a zombie-like blank stare (hence the nickname) was discovered in the body of a buck in Yellowstone National Park in October and has now reportedly spread spread to 32 US states. states and four Canadian provinces. It has reportedly been found in 800 samples of deer, elk and elk throughout Wyoming.
The spread has led experts to express concerns about the potential jump to humans, with one expert calling it a “slow-moving disaster”. CWD researcher Dr Cory Anderson told The Guardian: “The outbreak of mad cow disease in Britain was an example of how things can go crazy overnight if there is a spillover event from, for example, cattle to people. We’re talking about the potential of something similar happening. No one is saying it will definitely happen, but it is important that people are prepared.’
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What is zombie deer disease?
Zombie deer disease is the name given to chronic wasting disease (CWD), a prion disease that affects deer, elk, reindeer, sika deer and elk. Prion proteins appear on the surface of cells and when they become abnormal, they can cause diseases that are transmissible, untreatable and neurodegenerative in humans and animals.
CWD can affect animals of all ages, and some infected animals may die without ever developing the disease. It can take more than a year for animals with CWD to develop symptoms, but CWD is fatal and there are no treatments or vaccines.
The UK government website describes CWD as a “highly contagious and fatal disease affecting most wild and farmed deer species” including: elk, moose, mule deer, white-tailed deer, red deer, roe deer, reindeer, North American elk. (known in Europe as elk), white-tailed deer (native to North America), fallow deer, sika, Chinese water deer and muntjac.
It adds: “Humans are not affected, nor are animal products or meat such as venison.”
What are the symptoms of zombie deer disease?
Symptoms develop about a year after the animal becomes infected. Symptoms may include drastic weight loss (wasting), stumbling, wobbling and lethargy, drooling, aggression, and other neurological symptoms.
The symptoms have led many to call CWD “zombie deer disease” because the deer affected by it resemble zombies due to their lethargy and blank stare.
The government website points to behavioral changes including: separation from other animals in the herd; depression or blank facial expression; lowering of the head; Difficulty swallowing; increased thirst and urination; drooling; pneumonia; less interest in hay, but continue to eat grain; grinding of teeth and nervousness and excitement.
It added that infected deer may: stumble and have poor coordination; be listless and dull; walk in fixed and repeating patterns; have vibrations; have paralysis.
What areas are affected by zombie deer disease?
According to the U.S. Centers for Disease Control and Prevention (CDC), the disease was first identified in captive deer at a research facility in Colorado in the late 1960s, and in wild deer in 1981. In the 1990s, the disease was also identified in surrounding areas reported. in northern Colorado and southern Wyoming.
Since 2000, the area known to be affected by CWD in free-ranging animals has increased to at least 31 states in all four regions of the US. Once CWD has become established in an area, the risk can persist in the environment for a long time.
A deer carcass in Yellowstone National Park tested positive for the disease in mid-November. According to the CDC, “as of November 2023, CWD has been reported in free-ranging deer, elk, and/or moose in at least 31 states in the continental United States, as well as three provinces in Canada.”
Cases have also reportedly been reported in Norway, Finland, Sweden and South Korea. According to the government website, there have been no outbreaks in Britain, but in 2016 CWD was diagnosed in wild deer in Norway, the first cases of CWD in Europe.
Why are scientists worried it could spread to humans?
According to the CDC, no cases of CWD infection in humans have been reported to date. But it says some animal studies suggest CWD poses a risk to certain species of non-human primates, such as monkeys, that eat meat from CWD-infected animals or come into contact with brain or body fluids from infected deer or elk.
However, CWD researcher Dr. Cory Anderson suggested that it is important to be prepared for the possibility that the disease could spread to people. He told The Guardian: “The outbreak of mad cow disease in Britain was an example of how things can go crazy overnight if there is a spillover event from, for example, cattle to people. We’re talking about the possibility that something similar could happen. No one is saying it will definitely happen, but it is important that people are prepared.”
The CDC has urged people to “test hunted animals before eating meat; avoid deer and elk that look sick, behave strangely, or are found dead; use latex or rubber gloves when removing the internal organs of hunted deer, while minimizing contact with the brain. and spinal cord tissue; do not use household knives or utensils when handling venison”.
It points out that since 1997, the World Health Organization has recommended that it is important to prevent the causative agents of all known prion diseases from entering the human food chain.
Can zombie deer disease be cured?
CWD is fatal to animals and there are no treatments or vaccines. It can affect animals of all ages and some infected animals may die without ever developing the disease.
According to the CDC, prions can also remain in environments for long periods of time, increasing concerns about the spread of CWD.
Which animal diseases have previously caused outbreaks in humans?
There have been several cases in the past where diseases in animals have spread to humans.
They contain:
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Rabies: This zoonotic viral disease affects the central nervous system and is virtually 100% fatal once clinical symptoms appear. According to the WHO, rabies spreads to humans and animals through saliva, usually through bites, scratches or direct contact with mucous membranes (e.g. eyes, mouth or open wounds) and in up to 99% of cases, domestic dogs are responsible for transmitting the rabies virus for people.
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Bird flu: Bird flu, also known as bird flu, is a contagious form of flu that spreads among birds. In rare cases it can affect people. According to the NHS website, there are many different strains of the bird flu virus and most do not infect humans, but there are four strains that have caused concern in recent years. Bird flu is spread by close contact with an infected bird, including: touching infected birds; touching droppings or litter o killing or preparing infected poultry for cooking.
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Mad cow disease: In the 1980s and 1990s, bovine spongiform encephalopathy (BSE) – also known as ‘mad cow disease’ – was found to have spread from animals to humans in Britain after people ate cattle infected with BSE. People can get a version of BSE called variant Creutzfeldt-Jakob disease (vCJD), and according to US FDA figures, 232 people have died from vCJD since 2019. Neither vCJD nor BSE is contagious, so people cannot contract the disease if they are around a sick person or cow, or if they drink milk or eat dairy products.
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COVID: Some believe the COVID-19 pandemic, which has affected the entire world, has spread from animals at a wet market in Wuhan, China, to humans.