BayCEER Workshop 2023

Global biogeography of bat-associated viruses

Bats are one of the most species-rich orders of mammals and harbour a highly diverse virome. Some bat-associated viruses have spilled over to humans, livestock, and other mammals, causing zoonotic diseases. However, an overview on the diversity and biogeography of bat-associated viruses is missing, but highly relevant for Planetary Health. Here, we provide a biogeographic overview of global hotspots and biogeographic patterns of bat-associated virus richness in relation to biomes and continents. Publicly available data on bat-associated viruses was combined with data on bat distribution to identify hotspots and biogeographic patterns of bat-associated virus richness. In general, bat-associated virus richness increases from the poles to the equator, following bat species α-diversity. Southeast Asia, tropical Africa and Central America form distinct hotspots of virus richness. Biogeographic patterns for virus families differed. Rhabdoviridae and Herpesviridae display high richness in the Americas, whereas Coronaviridae richness is highest in Southeast Asia as well as tropical Africa. Moreover, bat-associated Astroviridae richness is highest in Southeast Asia, Paramyxoviridae richness is highest in tropical Africa, and Adenoviridae richness is highest in tropical Africa and Europe. However, biomes and continents as potential underlying drivers only explain a low amount of the observed variance. The here identified hotspots of bat-associated virus richness may harbour potentially zoonotic viruses. However, these hotspots need to be considered with caution due to biases and knowledge gaps. Only 353 out of the 1,449 currently accepted bat species have been associated to viruses. The knowledge gaps on bat-associated viruses are particularly high in tropical regions, which are known hotspots of bat diversity. Therefore, future research efforts are needed to sharpen our understanding of the bat virome and to identify potential areas at risk for future spillover events.