Investigation of Tick-Borne Pathogens in <i>Ixodes</i> Ticks from Bosnia and Herzegovina

Limited information is available regarding the presence of tick-borne pathogens and their distribution within <i>Ixodes</i> species in Bosnia and Herzegovina. This study aimed to identify <i>Rickettsia</i> spp., <i>Babesia</i> spp., <i>Anaplasma phagocytophilum</i>, and <i>Borrelia burgdorferi</i> sensu lato (s.l.) in <i>Ixodes</i> ticks collected from domestic and wild animals and vegetation in different regions across Bosnia and Herzegovina. A total of 7438 adult ticks, including 4526 <i>Ixodes ricinus</i>, <i>Ixodes canisuga</i>, and <i>Ixodes hexagonus</i>, were collected. Real-time PCR screening of 450 pooled <i>I. ricinus</i> samples revealed a 22.1% infection rate with at least one pathogen. <i>Rickettsia</i> spp. (6.3%) were found in ticks from dogs, cats, and goats, <i>Babesia</i> spp. (3.1%) in ticks from dogs and cattle, <i>A. phagocytophilum</i> (8.8%) in ticks from dogs, goats, and cattle, and <i>B. burgdorferi</i> s.l. (3.4%) in ticks from dogs and cats. Mixed infections with <i>B. burgdorferi</i> s.l. and <i>A. phagocytophilum</i>, as well as <i>B. burgdorferi</i> s.l. and <i>Rickettsia</i> spp., were found in two pools of <i>I. ricinus</i> from dogs and cats, respectively. Additionally, co-infection with <i>Rickettsia</i> spp. and <i>A. phagocytophilum</i> was confirmed in three tick pools from dogs and goats. Each tick from these pooled samples was individually retested to confirm the presence of pathogens. In the examined pooled samples of <i>I. canisuga</i> (1) and <i>I. hexagonus</i> (6), none of the tested pathogens were detected. Our findings represent the first detection of <i>Rickettsia</i> spp., <i>Babesia</i> spp., <i>A. phagocytophilum</i>, and <i>B. burgdorferi</i> s.l. in <i>I. ricinus</i> collected from domestic animals and vegetation in Bosnia and Herzegovina. Considering the established infection rates, the detection of tick-borne pathogens in adult ticks collected from domestic animals and vegetation enriches the current knowledge of the presence of tick-borne pathogens at the local, regional, national, and broader levels.