Possibility for reverse zoonotic transmission of SARS-CoV-2 to free-ranging wildlife: A case study of bats

Abstract

The COVID-19 pandemic highlights the substantial public health, economic, and societal consequences of virus spillover from a wildlife reservoir. Widespread human transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) also presents a new set of challenges when considering viral spillover from people to naïve wildlife and other animal populations. The establishment of new wildlife reservoirs for SARS-CoV-2 would further complicate public health control measures and could lead to wildlife health and conservation impacts. Given the likely bat origin of SARS-CoV-2 and related beta-coronaviruses (β-CoVs), free-ranging bats are a key group of concern for spillover from humans back to wildlife. Here, we review the diversity and natural host range of β-CoVs in bats and examine the risk of humans inadvertently infecting free-ranging bats with SARS-CoV-2. Our review of the global distribution and host range of β-CoV evolutionary lineages suggests that 40+ species of temperate-zone North American bats could be immunologically naïve and susceptible to infection by SARS-CoV-2. We highlight an urgent need to proactively connect the wellbeing of human and wildlife health during the current pandemic and to implement new tools to continue wildlife research while avoiding potentially severe health and conservation impacts of SARS-CoV-2 "spilling back" into free-ranging bat populations.

Fig 1. Global patterns of bats and associated β-CoVs.

(A) Red-shaded distributions of bat species in which SARS-related β-CoVs of the subgenus Sarbecovirus have been detected; (B) pink-shaded distributions of bat species known to host β-CoVs of the subgenus Hibecovirus; (C) brown-shaded distributions of bats in which β-CoVs of the Nobecovirus lineage have been detected; and (D) green-shaded distributions of bats known to host MERS-related β-CoVs of the subgenus Merbecovirus. Different colors and shade styles within each panel represent different families of bats. A data table that includes all known bat species associations for each β-CoVs subgenus and peer-reviewed citations is available at US Geological Survey data release https://doi.org/10.5066/P9U461PJ. Maps created using ArcMap (ESRI, Redlands, California, United States of America) and bat ranges derived from spatial data on terrestrial mammals from the International Union for the Conservation of Nature (IUCN 2020. The IUCN Red List of Threatened Species. January 2019 [version 6.2]. https://www.iucnredlist.org; Downloaded on 11 April 2020). β-CoV, beta-coronavirus; MERS, Middle East respiratory syndrome; SARS, severe acute respiratory syndrome.

Fig 2. Old-World and New-World bats.

Overlapping species distribution outlines of bats in the globally distributed suborder Yangochiroptera (blue) and Old-World Yinpterochiroptera (yellow). Maps created using ArcMap (ESRI, Redlands, California, USA) and bat ranges derived from spatial data on terrestrial mammals from the International Union for the Conservation of Nature Red List of Threatened Species, January 2019 [version 6.2]. https://www.iucnredlist.org; Downloaded on 11 April 2020.