The deadly disease CWD is apparently spreading in the famous US National Park Yellowstone. Now fears about the risks among people are growing.
Fears of a deadly disease affecting wild animals are spreading in the famous Yellowstone National Park in the USA. In November, the first dead mule deer tested positive for Chronic Wasting Disease (CWD). This is an infectious disease of the central nervous system, which is also called “zombie disease” because of its symptoms.
In recent years, the disease has continued to spread in the USA. This first confirmed case in the famous nature reserve now raises questions about possible risks to humans. So far, nothing is known about transmission to people or pets. But some experts express concern that it could spread to other species – including humans.
“It’s important that people are prepared for this”
CWD has similarities to BSE, mad cow disease. Epidemiologist Cory Anderson told the Guardian: “The BSE outbreak in Britain was an example of how everything can go crazy overnight if a spillover event spreads from livestock to humans, for example.” And further: “We are talking about the possibility that something similar could happen. Nobody is saying that it will definitely happen, but it is important that people are prepared for it.”
Like BSE, CWD is not caused by bacteria or a virus, but by prions, i.e. misfolded proteins. The disease attacks the central nervous system, causing infected animals to become increasingly emaciated and weak.
Contaminated meat could be dangerous
The disease has been appearing again and again in the USA and Canada for years; in Europe, the first case was detected in a moose in Finland in 2018. As early as 2019, researcher Michael Osterholm warned that transmission to humans could not be ruled out. “It is likely that human cases of CWD linked to consumption of contaminated meat will be documented in the coming years,” warned the director of the Center for Infectious Diseases at the University of Minnesota in 2019.
Other researchers, however, disagreed. The Friedrich Loeffler Institute reports that, according to studies, there appears to be a significant species barrier in the transmission of CWD to humans. There is also no evidence of CWD transmission to humans. “According to current scientific knowledge, transmission of CWD to humans cannot be ruled out with absolute certainty, but the risk of this can be assumed to be extremely low,” the institute announced in 2019.
Expert: eruption in Yellowstone is an important alarm signal
After the case in Yellowstone Park became known, both the US health authority CDC and individual states urgently recommended that hunted game be tested for diseases. Consumers should also not consume meat from animals that appear sick.
Yellowstone Park is one of the areas with the largest and most diverse population of large wild animals in the United States. The veterinarian and former head of animal health at the US Fish and Wildlife Service spoke of an important alarm signal that CWD has now been detected there. “This case puts CWD in the spotlight in a way it hasn’t been before – and that’s ironically a good thing,” he told the Guardian.
The authorities are now trying to contain the spread. Another problem is that people feed the animals in the national park. “The science about what is needed to slow the spread of CWD is clear and has been known for a long time,” Roffe told the Guardian. “You don’t feed wildlife in the face of a growing disease pandemic.”