Bats & Bird Flu: Potential New Wild Card | UNMC News

Bats have been identified as the latest mammals susceptible to H5N1, the highly pathogenic avian influenza virus responsible for bird flu, raising concerns about potential mutations and spread, according to research reported November 11, 2025, at bioRxiv.org and detailed in Science News.

Researchers in Peru have found over a dozen vampire bats carrying H5N1 antibodies, indicating exposure to the virus. This discovery is “very worrisome,” according to Vincent Munster, a virus ecologist at the Rocky Mountain Laboratories in Hamilton, Mont., who was not involved in the study. Each new mammalian host provides the virus with opportunities to mutate and evolve, potentially increasing the risk of transmission to humans.

Bat Species at Risk

Vampire bats may not be the only species at risk. Preliminary findings from Bangladesh suggest that 16 flying foxes, large fruit-eating bats, may have died from bird flu. Munster is currently investigating these deaths.

The potential for bats to act as reservoirs for the virus is a significant concern. Gregory Gray, an infectious diseases epidemiologist at the University of Texas Medical Branch in Galveston, who was not involved in either of the bat studies, explained that if multiple bat species are susceptible to H5N1, large colonies could maintain the virus and potentially transmit it to other animals or even humans.

Vampire Bat Research in Peru

Wildlife veterinarian I-Ting Tu began her Ph.D. At the University of Glasgow in Scotland in the summer of 2023, focusing on viruses that vampire bats (Desmodus rotundus) might transmit to marine animals in Peru. This research contributed to the identification of H5N1 exposure in the bat population.

The findings highlight the importance of monitoring wildlife for avian influenza and understanding the potential for cross-species transmission. The virus’s ability to jump to new mammalian hosts is a key factor in its evolution and potential to pose a greater threat to public health.

Broader Context of H5N1

H5N1 is a highly pathogenic avian influenza virus that has been causing outbreaks in wild birds and poultry. While sporadic human cases have been reported, the virus has not yet demonstrated efficient human-to-human transmission. However, the emergence of the virus in mammalian hosts like bats raises concerns about the potential for mutations that could increase its transmissibility.

The Centers for Disease Control and Prevention (CDC) is closely monitoring the situation and providing guidance on preventing the spread of bird flu. The CDC website provides up-to-date information on H5N1 outbreaks, symptoms, and prevention measures.

The discovery of H5N1 in bats underscores the complex dynamics of zoonotic diseases – diseases that can transmit from animals to humans – and the need for continued surveillance and research to mitigate the risk of future pandemics.