In new research, a team of scientists from Virginia Tech examined how widespread exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has been in wildlife communities between May 2022 and September 2023 across Virginia and Washington, D.C. They documented positive detections of SARS-CoV-2 RNA in six species, including the deer mouse, Virginia opossum, raccoon, groundhog, Eastern cottontail, and Eastern red bat. They also found no evidence of the SARS-CoV-2virus being transmitted from animals to humans, and people should not fear typical interactions with wildlife.
Goldberg et al. suggest that a broad diversity of mammal species have been exposed to SARS-CoV-2 in the wild. Image credit: Goldberg et al., doi: 10.1038/s41467-024-49891-w.
“SARS-CoV-2 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 Virginia Tech’s Professor Carla Finkielstein.
“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 new study significantly expands the number of species examined and the understanding of virus transmission to and among wildlife.
The data suggest 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.
“This study was really motivated by seeing a large, important gap in our knowledge about SARS-CoV-2 transmission in a broader wildlife community,” said Virginia Tech’s Dr. Joseph Hoyt.
“A lot of studies to date have focused on white-tailed deer, while what is happening in much of our common backyard wildlife remains unknown.”
For the study, the researchers collected 798 nasal and oral swabs across from animals either live-trapped in the field and released, or being treated by wildlife rehabilitation centers. 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 scientists also identified two mice at the same site on the same day with the exact same variant, indicating they either both got it from the same human, or one infected the other.
They are not certain about the means of transmission from humans to animals. One possibility is wastewater, but trash receptacles and discarded food are more likely sources.
“I think the big take home message is the virus is pretty ubiquitous. We found positives in a large suite of common backyard animals,” said Virginia Tech’s Dr. Amanda Goldberg.
“This study highlights the potentially large host range SARS-CoV-2 can have in nature and really how widespread it might be,” Dr. Hoyt said.
“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.”
“But what we’ve already learned is that SARS CoV-2 is not only a human problem, and that it takes a multidisciplinary team to address its impact on various species and ecosystems effectively,” Professor Finkielstein said.
The findings appear today in the journal Nature Communications.
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A.R. Goldberg et al. 2024. Widespread exposure to SARS-CoV-2 in wildlife communities. Nat Commun 15, 6210; doi: 10.1038/s41467-024-49891-w
This article was adapted from an original release by Virginia Tech.
Source : Breaking Science News