Synanthropic birds associated with high prevalence of tick-borne rickettsiae and with the first detection of Rickettsia aeschlimannii in Hungary.

The aim of this study was to analyze synanthropic birds as risk factors for introducing ticks and tick-borne pathogens into human settlements, with an emphasis on rickettsiae. Altogether 184 subadult ticks were found on 5846 birds. Tick infestation was most prevalent during the spring. In this sample group the majority of ticks were molecularly identified as Ixodes ricinus, and three individuals collected from the European robin as Hyalomma marginatum marginatum. The latter is the first molecularly confirmed occurrence of this species in Hungary. Rickettsia aeschlimannii was detected in H. marginatum, also for the first time in Hungary, and in ticks from an urbanized bird species north of the Mediterranean countries. The overall prevalence range of rickettsiae (including R. helvetica and R. monacensis) in ticks of synanthropic birds was 29-40%, exceeding that in questing ticks of relevant species reported earlier. Additionally, in specimens of I. ricinus, the presence of Borrelia burgdorferi sensu lato (s.l.), Anaplasma phagocytophilum, and a new Francisella-like genotype was also verified. Thus, it can be concluded that birds with urban or periurban habitats pose a high risk as tick carriers and reservoirs of zoonotic agents, especially of rickettsiae.