SARS-CoV-2, the virus responsible for COVID-19, is widespread among wildlife species. A new study from Virginia Tech finds that the virus was detected in six common garden species. In addition, antibodies indicating prior exposure to the virus were found in five species with rates of exposure ranging from 40 to 60 percent depending on the species.
The research was led by scientists at the Fralin Biomedical Research Institute at VTC, the Department of Biological Sciences in Virginia Tech’s College of Science, and the Fralin Life Sciences Institute.
The research is based on the genetic tracking in wild animals confirmed both the presence of SARS-CoV-2 and the existence of unique viral mutations with lineages closely matching variants circulating in humans at the time, further supporting human-to-animal transmission.
For this the researchers tested animals from 23 common Virginia species for both active infections and antibodies indicating previous infections. The scientists found signs of the virus in deer mice, Virginia opossums, raccoons, groundhogs, Eastern cottontail rabbits, and Eastern red bats.
The virus isolated from one opossum showed viral mutations that were previously unreported and can potentially impact how the virus affects humans and their immune response.
The highest exposure to SARS CoV-2 was found in animals near hiking trails and high-traffic public areas in the U.S., suggesting the virus passed from humans to wildlife.
The scientists collected 798 nasal and oral swabs across in Virginia from animals either live-trapped in the field and released, or being treated by wildlife rehabilitation centres. They also obtained 126 blood samples from six species. The locations were chosen to compare the presence of the virus in animals in sites with varying levels of human activity, from urban areas to remote wilderness.
The findings highlight the identification of novel mutations in SARS-CoV-2 in wildlife and the need for broad surveillance. These mutations could be more harmful and transmissible, creating challenges for vaccine development.
There was, however, found no evidence of the virus being transmitted from animals to humans, and people should not fear typical interactions with wildlife. Hence, the researchers are not certain about the means of transmission from humans to animals. One possibility is wastewater, another is trash receptacles and discarded food.
“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 Carla Finkielstein, professor of biological sciences at the Fralin Biomedical Research Institute at VTC.
She adds: “The goal of the virus is to spread in order to survive. 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 were previously identified in wildlife, primarily in white-tailed deer and feral mink. The Virginia Tech study expands the number of species examined and the understanding of virus transmission to and among wildlife. The data suggests exposure to the virus has been widespread in wildlife and that areas with high human activity may serve as points of contact for cross-species transmission.
The findings point to the fact that the virus is indifferent to whether its host walks on two legs or four. Its primary objective is survival.
The research has been published in the journal Nature Communications. The paper is titled “Widespread exposure to SARS-CoV-2 in wildlife communities.”
