A wild American mink in Utah has tested positive for the coronavirus — the first wild animal found to be infected with the virus, researchers say.
The wild mink was infected with a variant of the coronavirus that was “indistinguishable” from viruses taken from nearby farmed minks, researchers with the U.S. Department of Agriculture wrote in a Dec. 13 report. That suggests that the wild mink acquired the infection from farmed animals. It’s not clear if the animal was alive or dead at the time of testing.
Researchers found the mink during a survey for coronavirus-infected wildlife in areas surrounding mink farms that had outbreaks from August 24 to October 30. With only one wild animal testing positive so far, there is no evidence that the coronavirus, called SARS-CoV-2, is spreading among wild animals in the United States or elsewhere.
If the virus were to become widespread among wild or farmed minks, it may continue to evolve in those animals. In such a scenario, the virus could accumulate mutations that might not occur in humans, potentially allowing the virus to jump to other types of animals and make them sick or transmit a new, possibly more virulent strain back to people.
There have been multiple coronavirus outbreaks on mink farms in the United States and Europe since the COVID-19 pandemic began. While infected people originally passed the virus to farmed animals, small genetic changes in viruses infecting people and minks in Europe show that the coronavirus has also spread from mink back to humans, researchers reported in November in Science.
Millions of animals in Denmark were culled in early November after authorities raised concerns that mutations in mink versions of the coronavirus might make COVID-19 vaccines less effective. That could happen if the parts of the virus that are typically the target of protective, vaccine-induced antibodies evolve in minks to escape recognition and then those viruses are passed to people. But there is no evidence suggesting that existing viral variants from minks can weaken vaccines.