Tick-Borne Pathogens in Wild Cervids from Poland: A Molecular Survey on Anaplasma phagocytophilum and Piroplasms

Tick-borne diseases (TBDs) are important infections affecting animal health, and some are zoonotic. Understanding the distribution of TBDs in wildlife is important to evaluate the role of wild animals in the maintenance and spread of tick-borne pathogens (TBPs) in natural ecosystems. This study investigates the occurrence of selected TBPs, including Anaplasma phagocytophilum and piroplasms (Babesia spp. and Theileria spp.), in three widespread wild cervids from Poland: red deer, fallow deer, and roe deer. Ninety spleen tissue samples (30 per species) were collected and analyzed by endpoint PCR and sequencing. DNA of A. phagocytophilum was detected in 54.6% of the samples, mainly in red deer (75.9%), followed by fallow deer (46.4%) and roe deer (41.4%). Piroplasm DNA was found in 30% of the samples, with the highest prevalence in red deer (47%), followed by fallow deer (27%) and roe deer (17%). Sequencing analysis showed the presence of Theileria capreoli and identified two distinct genotypes: "elaphi-CE1", associated with red deer and fallow deer, and "capreoli-CE1", associated with roe deer. The results update the epidemiology of TBPs in Poland, supporting the role of cervids as potential reservoirs of A. phagocytophilum and T. capreoli, confirming the need for surveillance in wildlife. Further studies are needed to investigate the distribution of T. capreoli genotypes across Europe.