Scientists have warned that “zombie deer disease” could spread to humans after hundreds of animals contracted the disease in the US last year.
Chronic wasting disease (CWD) has been found in 800 samples of deer, elk and moose in Wyoming, where the animals are drooling, lethargic, limp and blank-eyed.
But experts warned the disease was a “slow-moving disaster” and urged governments to prepare for the possibility that it could spread to humans.
“The mad cow disease outbreak in Britain provided an example of how, overnight, a spillover event from humans to livestock can lead to madness,” CWD researcher Dr Cory Anderson told The Guardian.
“We're talking about the possibility of something similar happening. No one is saying it will definitely happen, but it's important that people are prepared,” he said.
In the UK, 4.4 million cattle were killed during the 1980s and 1990s due to outbreaks of bovine spongiform encephalitis, which were fed contaminated meat and bone meal to cows.
The disease, usually fatal to cattle, affects the central nervous system, leaving animals with aggressive symptoms and lack of coordination. Since 1995, 178 human deaths have been attributed to human variation.
According to the Coalition for Public Wildlife, in 2017, between 7,000 and 15,000 CWD-infected animals were consumed by humans a year.
This figure was expected to rise by 20 percent annually. In Wisconsin, thousands of people may have eaten meat from infected deer, Dr. Anderson said.
CWD is very difficult to eradicate once an environment is infected. It can remain on dirt or surfaces for years, and is resistant to disinfectants, formaldehyde, radiation and incineration at temperatures of 600C (1,100F), scientists report.
It comes after US biotech company Ginkgo Bioworks warned that diseases transmitted from animals to humans could kill 12 times more people in 2050 than in 2020.
The agency said outbreaks of zoonotic diseases – known as spillover – are likely to become more frequent in the future due to climate change and deforestation.
According to the team's research, between 1963 and 2019, infections increased by nearly 5 percent each year, while deaths increased by 9 percent.
“If these annual rates of increase continue, we expect the analyzed pathogens to cause four times the number of cases and 12 times the number of deaths in 2050 than in 2020,” it warned.