Molecular surveillance of tick-borne pathogens in wild mammals from Poland: host-specific patterns of Babesia spp. and Anaplasma phagocytophilum

Abstract Tick-borne diseases are increasingly threatening human and animal health in Europe, yet molecular data from wild mammals in Poland remain limited. This study investigated the prevalence of selected tick-borne pathogens in large wild mammals from Poland. Spleen samples from 315 animals including roe deer ( Capreolus capreolus ), European bison ( Bison bonasus ), wild boar ( Sus scrofa ), and grey wolves ( Canis lupus ) were collected between 2020 and 2024, and tested by PCR for the Babesia spp., Theileria spp., Anaplasma spp., Borrelia burgdorferi sensu lato, and Rickettsia spp., followed by sequencing. Anaplasma phagocytophilum and Babesia spp. were each detected in approximately 6% of samples, whereas Theileria spp., Borrelia spp. and Rickettsia spp. were absent. Roe deer showed the highest prevalence of Babesia spp., mainly B. capreoli , with occasional detections of B. venatorum . A. phagocytophilum was detected in all host species, with the highest prevalence in European bison. These results highlight roe deer as a key reservoir for Babesia spp. and demonstrate widespread circulation of A. phagocytophilum in Polish wildlife.