Corona/CoViD-news

Deer mice, opossums, raccoons, groundhogs, Eastern cottontail rabbits, and Eastern red bats had signs of infection, and isolates from an opossum showed previously unreported viral mutations closely matching the SARS-CoV-2 Omicron variant circulating in people at the time, which the authors said suggests at least seven recent human-to-animal virus transmission events. The mutations could alter the virus's effects on people.

The team also identified two mice on the same day with the same variant, indicating that one mouse infected the other or that they both were infected by the same person.

Further supporting human-to-animal viral spread was the finding of the highest SARS-CoV-2 antibody seroprevalence near hiking trails and other public areas. Some opossums, raccoons, Eastern gray squirrels, white-footed mice, and deer mice had SARS-CoV-2 antibodies.

Transmission could have taken place via wastewater, trash bins, or discarded food. There was no evidence of animal-to-human transmission.

"The virus can jump from humans to wildlife when we are in contact with them, like a hitchhiker switching rides to a new, more suitable host," co-senior author Carla Finkielstein, PhD, said in a Virginia Tech press release. "The virus aims to infect more humans, but vaccinations protect many humans. So, the virus turns to animals, adapting and mutating to thrive in the new hosts."

SARS-CoV-2 infections have been previously identified in wildlife such as white-tailed deer and mink. "The virus is indifferent to whether its host walks on two legs or four," Finkielstein said. 

The study team called for more research into how SARS-CoV-2 spreads from people to wildlife, within species, and from one species to another.