Zoonotic pathogens in the ectoparasites of European bats: a review

Abstract

Bats are an important group of mammals that perform significant ecological functions, such as regulating insect populations, pollinating plants, and dispersing seeds. However, these animals also host a wide range of ectoparasites, which may harbour microorganisms of public health importance. This review summarises data on potentially zoonotic and vector-borne microorganisms detected in the ectoparasites of European bats between 2010 and 2025. The review is based on 17 scientific publications investigating bat-associated ectoparasites, including ticks, bat flies, fleas, mites and bat bugs, from twelve European countries. The reviewed studies reported microorganisms belonging to the genera Bartonella, Rickettsia, Borrelia, Anaplasma, Ehrlichia, Babesia, Mycoplasma and Neoehrlichia. Bartonella spp. were the most frequently detected microorganisms and were reported in several ectoparasite groups, particularly bat flies, fleas, and mites. In contrast, Rickettsia, Borrelia, Ehrlichia, and Babesia were most commonly associated with bat ticks. Most studies were conducted in Central and Eastern Europe, whereas some European regions remain poorly investigated. The detection of microbial DNA in bat ectoparasites suggests that these ectoparasites may be involved in pathogen circulation; however, molecular evidence alone does not prove their ability to transmit pathogens to humans. Further studies are needed to better understand the role of bat ectoparasites in the circulation of microorganisms within bat populations.