Viral ecology in chiroptera: human-wildlife interactions and pandemic risk

Bats (Order Chiroptera) are ecologically essential and evolutionarily unique mammals, acting as a natural reservoir for innumerable viruses, including several with a high degree of zoonotic significance. The complex and intricate ecology of bat viromes results largely from species diversity, roosting patterns, social structures, immunological adaptations, and their remarkable longevity, especially compared to other small mammals such as rodents. These traits allow bats to carry pathogenic viruses without visible clinical symptoms over extended periods. This review delves into the virome of bat populations focusing on major families like Coronaviridae, Filoviridae, Paramyxoviridae and the evolutionary processes leading to their diversity, persistence within populations, and spill-over. The human-induced environmental disturbance in the form of deforestation, cultivation, urbanization, and wildlife trade has increased direct or indirect contact among bats, humans, and domestic animals, increasing the chances of spill-over. The study of historical events in the form of SARS, MERS, Nipah, Ebola is used for practical implications. We also discuss the behavioral and seasonal variations among intra-colony transmission, the role of intermediate hosts, and the critical need of having an effective One Health-based surveillance system. The understanding of ecological and evolutionary drives behind bat virome is necessary for anticipating zoonotic spill-over events, which can be used as a foundation for public health strategies. Finally, the necessity of integrating virology, ecology, and global health policy perspective in human health policy-making is also discussed, in the context of bat virome research, to prevent future pandemics.