• Posted July 29, 2024

COVID-19 Virus Is Widespread in U.S. Wildlife

The virus responsible for COVID-19 is widespread among wildlife, a new study finds.

SARS-CoV-2 was detected in six common backyard species, including deer mice, opossums, raccoons, groundhogs, cottontail rabbits and red bats, researchers reported July 29 in the journal Nature Communications.

Further, antibodies indicating prior exposure to the coronavirus were found in five animal species, with rates of exposure ranging from 40% to 60% between species.

The highest exposure to the COVID virus was found in animals near hiking trails and high-traffic public areas, suggesting that the virus passed from humans to wildlife, researchers said.

There was no evidence of COVID passing from animals to humans, so people don’t need to worry about getting the illness from any critters they come across while on a hike, researchers added.

“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,” said researcher Carla Finkielstein, a professor of biological sciences with Virginia Tech’s Fralin Biomedical Research Institute at VTC.

“The goal of the virus is to spread in order to survive. The virus aims to infect more humans, but vaccinations protect many humans,” Finkielstein added in a Virginia Tech news release. “So, the virus turns to animals, adapting and mutating to thrive in the new hosts.” 

SARS-CoV-2 infections have previously been found in wildlife, primarily in white-tailed deer and feral mink, researchers noted.

The new study significantly expands the number of species in which the COVID virus has been found, and suggests that areas with high human activity can serve as points of contact for transmission between humans and animals.

For the study, researchers collected nearly 800 nasal and oral swabs in Virginia from animals either live-trapped in the field and released or receiving treatment in a wildlife rehabilitation center.

The team also obtained 126 blood samples from six different species.

On one day, researchers identified two mice at the same site with the exact same COVID variant, indicating that they either both got it from the same human or one infected the other.

In addition, COVID isolated from one opossum showed viral mutations that had not been seen before, which could potentially make the virus more dangerous to humans.

“I think the big take-home message is the virus is pretty ubiquitous,” said lead researcher Amanda Goldberg, a former postdoctoral associate with the Virginia Tech College of Science. “We found positives in a large suite of common backyard animals.”

Many of the species that tested positive in Virginia are common throughout North America, and it’s likely they’re being exposed in other areas as well, Finkielstein said.

“The virus is indifferent to whether its host walks on two legs or four. Its primary objective is survival,” Finkielstein said. “Mutations that do not confer a survival or replication advantage to the virus will not persist and will eventually disappear.”

Surveillance for COVID transmission in animals needs to continue, and new mutations taken seriously as a potential threat to human health, researchers said.

“This study highlights the potentially large host range SARS-CoV-2 can have in nature and really how widespread it might be,” said researcher Joseph Hoyt, an assistant professor of biological sciences at Virginia Tech. “There is a lot of work to be done to understand which species of wildlife, if any, will be important in the long-term maintenance of SARS-CoV-2 in humans.”

More information

The U.S. Centers for Disease Control and Prevention has more about COVID-19.

SOURCE: Virginia Tech, news release, July 29, 2024