A strange illness called chronic wasting disease— or "zombie deer disease" — is on the move, with officials in several US states issuing warnings.
Currently, the disease is found in animals like deer, elk, and moose. It can take up to two years before signs of CWD become visible, but at some point, the illness will cause an infected deer to lose weight, stop interacting with other deer, and lose its fear of humans. The animal winds up staring vacantly as it starves to death, which is why the illness is also known as "zombie deer" disease.
Many animals are killed by predators or other diseases before they get to that final stage. But the condition, which is caused by the spread of misfolded proteins called prions, is fatal.
As far as we know, no human has ever been infected with chronic wasting disease. But researchers are concerned that if enough people eat infected meat from deer, elk, moose, and other CWD carriers, the illness could start to infect people.
In the US, CWD has now been found in 23 states. In Mississippi, an infected buck was recently discovered for the first time, according to local news reports. Officials from Minnesota's Department of Natural Resources have been encouraging hunters who own land in places where the disease is prevalent to harvest more deer so the carcasses can be tested, according to a report in the Star Tribune.
Why the condition's spread is disconcerting
Any new discovery of the disease, like the one in Mississippi, can indicate that more animals are infected. After a case was identified in Arkansas in 2016, dozens more were found in the following months.
The Minnesota Department of Natural Resources is attempting to reduce deer populations in infected areas. A DNR official told the Star Tribune that killing potentially affected deer could help the state stamp out the infection and avoid the rise of well-established infected populations like the ones in neighboring Wisconsin and Iowa.