Oral Sampling of Little Brown Bat (Myotis lucifugus) Maternity Colonies for SARS-CoV-2 in the Northeast and Mid-Atlantic, USA

Simple Summary A wide variety of coronaviruses are enzootic in bats worldwide. SARS-CoV-2, the virus responsible for the COVID-19 pandemic, is suspected to have originated in horseshoe bats (Rhinolophidae spp.) in Asia, though the spillover event is unknown. SARS-CoV-2 has not been detected in wild North American bats at the time of this submission, although it has been detected in other native wildlife, such as white-tailed deer (Odocoileus virginianus). Further interspecies transmission may establish new viral reservoirs and mutations which may negatively impact wildlife, livestock, and human health. The potential introduction of SARS-CoV-2 into North American bat populations is of interest to wildlife managers due to recent declines of several species, including little brown bats (Myotis lucifugus), which have suffered large population collapse due to white-nose syndrome (WNS). We analyzed saliva samples from 235 individual little brown bats from a total of eight maternity colonies throughout the Northeastern and Mid-Atlantic United States. No bat tested positive for SARS-CoV-2 by RT-qPCR, indicating the virus is either not present or that it persists in undetectable levels in little brown bat populations in this region. The potential introduction of SARS-CoV-2, the virus responsible for the COVID-19 pandemic, into North American bat populations is of interest to wildlife managers due to recent disease-mediated declines of several species. Populations of little brown bats (Myotis lucifugus) have collapsed due to white-nose syndrome (WNS), a disease caused by the introduction and spread of the fungal pathogen Pseudogymnoascus destructans (Pd). Throughout much of the United States and southern Canada, large colonies of the species routinely established diurnal roosts in anthropogenic structures, thereby creating the potential for direct human contact and cross-species disease transmission. Given recent declines and the potential for further disease impacts, we collected oral swabs from eight little brown bat maternity colonies to assess the presence and prevalence of SARS-CoV-2 by RT-qPCR analysis. Little brown bat colonies in Maryland (n = 1), New Hampshire (n = 1), New Jersey (n = 2), New York (n = 1), Rhode Island (n = 2), and Virginia (n = 1) were taken during May-August, 2022. From 235 assayed individuals, no bat tested positive for SARS-CoV-2. Our results indicate that little brown bats may not contract SARS-CoV-2 or that the virus persists at undetectable levels in populations of the Mid-Atlantic and Northeast during summer months. Nonetheless, continued monitoring and future work addressing other seasons may still be warranted to conclusively determine infection status.

Automated summary

A study was conducted on 235 little brown bats from the Northeastern and Mid-Atlantic United States, and no SARS-CoV-2 was detected in any of them. The potential introduction of the virus into North American bat populations is of interest to wildlife managers, especially in species that are already experiencing declines.