Fears ‘zombie deer disease’ could ‘pass to humans like mad cow disease’ after death of men

SCIENTISTS fear two men may have died of an animal disease that turns deers into 'zombies', sparking fears the bug could be passed on to humans.

The US hunters passed away in 2022 soon after eating deer meat, which scientists believe could have carried chronic wasting disease (CWD).

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The disease attacks the brain and nervous system, leaving animals drooling, lethargic, stumbling, and stick-thin.

The telltale blank stare of infected deer has led some to call CWD 'zombie deer disease'.

Some experts fear the illness could spill over to people in a similar way to mad cow disease back in the 90s.

But a new study, which goes into detail about the hunters' deaths, suggests the disease may already be spreading from animals to humans.

One of the victims discussed a 72-year-old man, suffered "rapid-onset confusion and aggression," as well as seizures.

He died within a month despite treatment.

After his death, he was diagnosed with Creutzfeldt-Jakob Disease (CJD), a brain-wasting condition responsible for mad cow disease. 

"The patient’s history, including a similar case in his social group, suggests a possible novel animal-to-human transmission of CWD," they wrote in the case report, published this month in the journal Neurology.

The hunter's friend also died from the disease, but experts didn't explain much about his condition.

The researchers are from Texas, but details about where the men lived or hunted were not shared.

What is chronic wasting disease?

CWD is caused by prions — a type of protein - which causes the brain to fold abnormally.

After infection, prions travel throughout the central nervous system, leaving prion deposits in brain tissues and organs. 

CWD affects deer, elk, moose, caribou and reindeer and is becoming more common.

It has been detected in 32 US states, three Canadian provinces, South Korea, Finland, Norway and Sweden.

It may take over a year for infected animals to develop symptoms, and they can die before they start drooling or get the “blank stare”.

There is currently no effective treatment or vaccine for the disease.

Like CWD, CJD is also caused by misfolded prions, though it most likely afflicts humans.

In most cases, CJD develops "sporadically" by causing the brain to fold abnormally.

The killer condition can also be inherited if one parent carries a mutation that causes prions to form in their brain during adulthood.

According to the NHS, the inherited form of the disease only affects about one in nine million people in the UK.

It's sometimes spread to humans from animals through contaminated meat, from a cow that had bovine spongiform encephalopathy, commonly known as "mad cow" disease.

Most people who have the disease die within a year of diagnosis.

The scientists never confirmed whether the specific deer that by the hunters was ever tested for CWD.

And because it is so difficult to distinguish between the two diseases, the researchers could not prove the men had picked up the infection from the deer meat.

However, there was a possibility of transmission due to both hunters' history of eating meat from that infected herd, they said.

"Although causation remains unproven, this cluster emphasises the need for further investigation into the potential risks of consuming CWD-infected deer and its implications for public health," the team wrote. 

'CWD might infect humans'

Alarms were sounded in December after hundreds of deer in Yellowstone National Park were found to have been infected with the highly contagious illness.

The Wyoming Game and Fish Department tested meat from 6,701 deer, elk and moose in 2022, detecting the disease in about 800 samples.

Separate research published in Acta Neuropathologica found “CWD might infect humans, although the transmission barrier is likely higher compared to zoonotic transmission of cattle prions”.

The study found that while mice could become infected with the disease, it did not cause the same symptoms as in deer, which include poor coordination, appearing listless and tremors.