SARS-CoV-2 Surveillance in Peri-Domestic and Wildlife Species in Ontario, Canada

Purpose The rapid emergence and spread of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has sparked concerns of spillover to naïve wildlife populations and it is unclear if wildlife could ultimately serve as a reservoir for the virus. Evidence of SARS-CoV-2 has been detected in captive and wild animals (e.g., mink, tiger, lion). Moreover, the SARS-CoV-2 variants of concern (VOCs) likely have a broader host range, suggested by the susceptibility of laboratory mice (Mus musculus) to the Beta and Gamma variants but not wild-type SARS-CoV-2. Peri-domestic animals (i.e., wild and feral animals living near humans) represent highly relevant species to assess spillover since they likely have a greater chance of exposure to the virus from humans. Thus, monitoring wildlife at the human-animal interface is critical in understanding the epidemiology of SARS-CoV-2. We therefore are investigating the presence of SARS-CoV-2 in key peri-domestic and wild animals across southern Ontario, Canada through a One Health framework. Methods & Materials In collaboration with the Ministry of Natural Resources and Forestry, oral and rectal swabs are opportunistically collected from two peri-domestic species, raccoons (Procyon lotor) and skunks (Mephitis mephitis), across southern Ontario where high population densities and incidence of SARS-CoV-2 in humans likely provide spillover opportunity. Additionally, oral and rectal swab, and respiratory and intestinal tissues from trapped wild mink (Neovison vison) are collected in collaboration with the Ontario Fur Managers Federation. Samples are analyzed at the Sunnybrook Research Institute via a RT-qPCR for two SARS-CoV-2 gene targets: the 5’ untranslated region (UTR) and the envelope gene (E). Results From September 2020 to January 2021, 264 oral and 264 rectal swabs were collected from 207 raccoons and 57 skunks. All samples were negative for SARS-CoV-2 RNA. The study is presently ongoing. Conclusion Based on these preliminary data, there is little evidence to suggest spillover of SARS-CoV-2 to the sampled animals during this period. Notably, these animals were sampled prior to the emergence of SARS-CoV-2 VOCs, and our results do not preclude the possibility of future spillover to wildlife at the human-animal interface. Results from ongoing surveillance efforts post-VOC emergence will also be discussed.