While SARS-CoV-2 has been documented in some wild animal species in the U.S., such as white-tailed deer, most species have not been tested for evidence of exposure or infection with the virus. With a $4.5 million grant from the U.S. Department of Agriculture, a team of researchers led by Penn State will collect samples from 58 species of wildlife — including eastern chipmunks, gray squirrels, raccoons, coyotes, white-footed mice, moose, wolverines, three species of deer and several species of bats — to test for SARS-CoV-2 with a goal of monitoring for potential spillback to humans.
According to Kurt Vandegrift, associate research professor of biology at Penn State and principal investigator of the project, in addition to identifying which species are infected with and transmit SARS-CoV-2, the team also plans to use viral characteristics to identify cross-species transmission events.
“We know that SARS-CoV-2 is currently circulating in some U.S. wildlife, which raises the potential for new variants to emerge,” Vandegrift said. “For example, recent evidence from deer in New York has revealed the continued circulation of variants long absent from the human population, indicative of persistence in the wild. Viral persistence is important because it not only poses a looming risk of spillback to humans, but also allows for viral evolution and the emergence of highly divergent variants for which our diagnostics, therapeutics and vaccines could be ill prepared.”
In addition to posing a potential threat to human health, Vandegrift said, the presence of the virus in wildlife poses a risk for spillover to agricultural animals which would threaten our food supply.
The team — which will also include co-principal investigators Suresh Kuchipudi, chair, Department of Infectious Diseases and Microbiology, University of Pittsburgh; Christopher Griffin, research professor, Applied Research Laboratory, Penn State; Peter Hudson, Willaman Professor of Biology, Penn State; Santhamni Ramasamy, postdoctoral fellow, University of Pittsburgh; and 40 undergraduate researchers — will sample over 20,000 individuals from 58 different species to document the presence of the virus.
Next, the team will use ‘capture-mark-recapture’ and ‘serial sampling’ methods, in which they will sample individuals within the same region multiple times to understand whether and how transmission is occurring. The researchers will then use a model-informed process to distinguish between ‘dead-end hosts,’ where the virus is not transmitted, and hosts that are responsible for onward transmission, both within and between species.
“Despite identification of SARS-CoV-2 infections in 29 non-human species and evidence of spillback into humans, the scientific community has not tested most of the species in the U.S. for evidence of exposure or infection with SARS-CoV-2,” Vandegrift said. “Our main goal is to fill this surveillance gap by obtaining and testing samples from many under-sampled species. By investigating transmission, we can inform interventions that prevent the spread of new variants. Overall, our goal is to safeguard the health of humans, wildlife and agricultural systems.”
The researchers are partnering with the Alaska and California Departments of Fish and Game; wildlife rehabilitation networks; nationwide pest control companies, including Critter Control, Trutech and Orkin; the Catalina Island Conservancy and the biotech company Ginkgo Bioworks.
“We are thrilled to collaborate with Penn State, a land-grant institution at the forefront of zoonotic SARS-CoV-2 biosurveillance, on this research," said Matt McKnight, general manager for biosecurity at Ginkgo Bioworks. "Partnerships between government, industry and academia are critical, and together we can build sustainable biosecurity infrastructure. By building a radar system for biological threats, including zoonotic diseases, we can give public health officials an early warning to support informed decision-making.”