Why Only Some Bats Harbor Dangerous Viruses

A new study published in Nature Communications Biology is reshaping how scientists view bats and the viruses they carry. Conducted by researchers at the University of Oklahoma, the work shows that only certain groups of bat species host highly virulent viruses, challenging the widespread belief that most bats serve as reservoirs for deadly pathogens.

Many highly consequential viruses, such as SARS-like coronaviruses, Marburg, Hendra, and Nipah, are known to originate in wildlife. Although bats have been linked to these diseases, they also provide vital ecosystem services. In Oklahoma, for instance, Mexican free-tailed bats feed on agricultural pests that threaten crops, while fruit bats play essential roles in pollination. “If we lost bats, agricultural production would be negatively affected, and so would economies,” said Caroline Cummings, lead author of the paper.

Using machine learning, Cummings and her team analyzed data from multiple bat species to determine which ones were more likely to carry high-risk viruses. Their findings showed that these traits tend to cluster among closely related bat groups. “Instead of all bats carrying all dangerous viruses, it’s only specific bats that have co‑evolved with specific viruses, and that’s why they tend to live with them and not be sick,” Cummings said.

As new human diseases emerge at increasing rates, this information could make viral surveillance more efficient. Monitoring wild species for potential zoonotic threats is intensive and costly, but narrowing the focus to high‑risk bat lineages could help target future testing efforts.

To refine these priorities, Cummings also mapped where high‑risk bat populations overlap with zones of heavy habitat disruption and human encroachment. When bat habitats are disturbed, direct contact between humans and bats rises, and stressed bats may shed more virus, heightening spillover risk. Protecting natural habitats, therefore, supports both ecological balance and public health.

“This work brings much‑needed nuance to discussions around bats and their role as viral hosts,” said Daniel Becker, senior author of the study. “The literature has often made broad, sweeping statements about bats and zoonotic risk. By being able to identify which particular groups of bat species carry dangerous viruses, and where they most overlap with human impacts, we can minimize negative human–bat interactions.”