Vampire bats found to carry bacteria infectious to humans & other animals at high rates
Bartonella spp. bacteria genotypes have wide spatial distribution across Latin America; transmission routes remain largely unknown
Bartonella are bacteria that cause endocarditis, a potentially life-threatening illness in humans and domestic animals. Vampire bats (Desmodus rotundus) in Latin America have a high prevalence of Bartonella and may transmit the bacterial infection to humans and livestock due to their subsistence on blood. A study published in PLOS Neglected Tropical Diseases by David Becker at the University of Georgia, in Athens, GA, 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 is known about the bats’ individual risk of infection and the genetic diversity of Bartonella bacteria in bat populations. Over a period of 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 in an attempt to shed light on possible bacteria transmission routes.
67% of tested bats were found to be Bartonella carriers; sex and forearm size were the strongest predictors of infection, with large males showing the highest risk. Genotypes were found to be be widely distributed across Central and South America, suggesting a limited spatial structure to infection transmission. 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 pathways 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.”