Molecular evidence of Anaplasma phagocytophilum and Babesia microti co-infections in Ixodes ricinus ticks in central-eastern region of Poland

The aim of the study was to elucidate the distribution of Anaplasma phagocytophilum and Babesia microti co-infection in Ixodes ricinus populations within the central-eastern region of Poland. The prevalence of analysed tick-borne human pathogens in single and polymicrobial infections in I. ricinus ticks were analysed using the conventional and nested PCR techniques. A total number of 1,123 questing tick individuals (291 females, 267 males and 565 nymphs) were collected at different ecosystems (municipal parks, suburban forests, and woodlands). In the presented study, 95 samples of ticks (8.5%) were infected with A. phagocytophilum, 3.1% (n=35) with B. microti, whereas the co-existence status of these human pathogens was detected in 1.8% (n=20) of all tested samples. It has been demonstrated that the prevalence of co-infection status was the highest among females of I. ricinus (11 samples, 3.8%), whereas the lowest within tested nymphs (5 samples, 0.9%). Ticks collected at city parks in Warsaw and suburban areas of this town characterized the highest prevalence of co-infections (3.3 and 4.8%, respectively). Furthermore, it was established that co-infection rates of ticks inhabiting woodlands within Kampinos National Park and Nadbużański Landscape Park were similar and reached the levels of 1.4% (n=5) and 1.1% (n=4), respectively.