RAPID: Evaluating the potential for SARS-CoV-2 spillback infections of native North American wildlife

SARS-CoV-2 originated from a bat, likely passing through another animal before it infected people. The objective is to determine if two North American native wildlife species can be infected with SARS-CoV-2, the causative agent of COVID-19, which to date has not been evaluated. Skunks and raccoons are closely related to other species that are known to be susceptible with this virus, and are highly abundant in human environments, frequently consuming human refuse. Both species are also handled frequently in wildlife research and rehabilitation settings?creating situations where spillback of the virus from people to them is likely. Further, this study will investigate whether skunk-to-skunk and racoon-to-raccoon transmission is possible, needed to forecast what would happen if this virus spilled into our native wildlife; the worst case scenario is that these species become reservoirs of the virus for people. Skunks and raccoons will be inoculated with two doses of SARS-CoV-2 that represent doses they might encounter the environment, or when in close contact with people. Nasal and fecal samples will be collected after inoculation and tested using two detection methods. Blood will also be collected at intervals to determine if these species create antibodies against the virus. In addition to rapidly disseminating this information to wildlife management agencies, presenting and publishing the results, this work will train three graduate and two undergraduate students on animal husbandry, experimental infections, and various laboratory analyses.

The objective of this study is to identify if two North American native wildlife species that represent a high likelihood of susceptibility and ecological opportunity?skunks and raccoons?are susceptible to infection with SARS-Cov-2. Current phylogenetic evidence indicates a spillover event from an animal host prompted the COVID-19 pandemic, thus, understanding susceptibility of animal species is paramount. Researchers will assess clinical outcome, duration and route of virus shedding, and seroconversion and pathology to understand the: 1) potential reservoir status of these common and abundant, peridomestic, mammalian wildlife species and, 2) likelihood of virus spillover from humans to these species. Results will guide proactive actions to manage contact between humans, domestic animals and wildlife?crucial to combat the ongoing COVID-19 pandemic. Animals will be acquired from a captive breeder and housed in BSL3 facility. Three pairs of each species will be intranasally inoculated with one of two doses of SARS-CoV-2 (103 and 105 plaque forming units). To determine direct contact transmission, at Day 1 post-inoculation, we will add one animal to each pair of inoculated animals. Post-inoculation, nasal and rectal swabs for qrtPCR and virus isolation and blood samples from both inoculated and direct contact animals will be collected up to 21 days. All animals will be monitored for clinical signs daily by a veterinarian and humanely euthanized, whereby a complete post-mortem examination will be conducted. This RAPID award is made by the Physiological and Structural Systems Cluster in the BIO Division of Integrative Organismal Systems, using funds from the Coronavirus Aid, Relief, and Economic Security (CARES) Act.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.