Diversity and dynamics of zoonotic pathogens within a local community of small mammals

Small mammals are important reservoirs of multiple pathogens transmittable to humans. Rodent populations are highly dynamic, passing through multiannual cycles with densities changing in several orders of magnitude. Such variable pools of hosts shape the intensity of pathogen spread among the animals and risks of spillover to humans. We describe such dynamic system within a sample set of 13 small mammal species and six potentially zoonotic pathogens (bacteria Anaplasma, Rickettsia , Leptospira, Borrelia, Bartonella , and protist Babesia ) present in surroundings of a small village in south-eastern part of the Czech Republic. This article presents results of a six-year-long study at the site. The observed prevalence of the selected pathogens varied greatly among years and host species. The dominant rodents ( Apodemus sp., Apodemus agrarius and Myodes glareolus ) harboured all tested pathogens and multi-infections were not rare – we found up to four pathogens in some individuals. We observed surge in Borrelia burgdorferi s.l. prevalence following the overall rodent population increase in 2014 and 2019, with A. agrarius and Microtus arvalis being the most infected species. Rickettsia sp. prevalence reached 24 % in the shrew Crocidura suaveolens , thus this potential neglected reservoir host deserves further attention.