Public Release: 

Vampire bats found to carry infectious bacteria at high rates

A PLOS Neglected Tropical Diseases press release



IMAGE: Common vampire bat (Desmodus rotundus) captured in Belize. view more 

Credit: Becker, et al (2018)

Bartonella are bacteria that cause endocarditis, a potentially life-threatening illness in humans and domestic animals. In Latin America, common vampire bats (Desmodus rotundus) are frequently infected by Bartonella, and their subsistence on blood creates a risk for bacterial transmission from bats to humans and livestock. A study published in PLOS Neglected Tropical Diseases by Daniel Becker at Montana State University in Bozeman, found Bartonella infections in vampire bats are highly prevalent in Peru and Belize, and that Bartonella genotypes are distributed widely, rather than clustered geographically.

Previous studies have suggested that vampire bats may be zoonotic reservoirs of Bartonella infections in humans, but little was known about the bats' individual risk of infection, the genetic diversity of Bartonella bacteria in bat populations, and how these bacteria may be transmitted among bats or to other species. Over two years, the researchers collected blood, saliva, and fecal samples from vampire bats across Belize and Peru. Samples were then tested to ascertain how many bats were infected. Individual risk factors for infection were identified by analyzing the relationship between bat age, sex, forearm size and reproductive status. Samples testing positive for Bartonella were then subjected to genomic sequencing and phylogenetic analysis to shed light on possible bacteria transmission routes.

67% of tested bats were found to be Bartonella carriers; with the highest risk of infection in large males. Bacterial genotypes were widely distributed across Central and South America, suggesting a limited spatial structure to infection transmission.

The researchers also investigated the how Bartonella might spread between individuals. While Bartonella spp. are often transmitted by biting arthropods, vampire bat saliva and fecal samples were also found to be positive for Bartonella, suggesting the possibility that transmission could occur through bites or environmental contamination. While these preliminary results provide insights about the infection rate among vampire bats and the genetic diversity of bat endemic Bartonella, more research is necessary to further elucidate transmission from bats to humans.

According to the authors, "Given the high rates of vampire bat bites and proximity to humans, and domestic animals, such efforts to verify the possibility and frequency of oral and environmental exposures would elucidate Bartonella transmission dynamics in this common host species and the risks of cross-species transmission."


Peer-reviewed / Observational Study / Bats

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Citation: Becker DJ, Bergner LM, Bentz AB, Orton RJ, Altizer S, et al. (2018) Genetic diversity, infection prevalence, and possible transmission routes of Bartonella spp. in vampire bats. PLOS Neglected Tropical Diseases 12(9): e0006786.

Funding: DJB was funded by a NSF Graduate Research Fellowship, ARCS Foundation Award, Sigma Xi, the Odum School of Ecology, the American Society of Mammalogists, the UGA Graduate School, the Explorer's Club, and NSF DEB-1601052. ABB was supported by a NSF Graduate Research Fellowship, the American Society of Mammalogists, and a UGA Global Programs International Travel Award. RJO was supported by the UK Medical Research Council (MC_UU_12014/12), SA acknowledges support from NSF DEB-1518611, and DGS was supported by a Sir Henry Dale Fellowship, jointly funded by the Wellcome Trust and Royal Society (102507/Z/13/Z). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing Interests: The authors declare that no competing interests exist.

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