Enzootic transmission cycles of tick-borne pathogen microorganisms

At least six pathogens that cause emerging tick-borne zoonoses and vector-transmitted diseases were identified in Europe (Rickettsia sp., Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato, Francisella tularensis, Crimean-Congo haemorrhagic fever virus, tick-borne encephalitis virus). Our preliminary research indicates the presence of A. phagocytophilum, F. tularensis, Rickettsia sp., and five genospecies of B. burgdorferi complex in ixodid ticks in Serbia. According to the epidemiological data, the tick-borne encephalitis virus and the Crimean-Congo haemorrhagic fever virus exist in natural foci of disease in Serbia, but systematic studies of their presence in ticks have not been realized yet. The planned research will include periodical material sampling (ticks from vegetation and hosts, serum and tissue samples of hosts) as well as cultivation, characterization, and genotypization of microorganisms. Seasonal dynamics of ticks, hosts, and pathogens will be monitored. Host exposure to tick-borne pathogens will be observed by serological tests. Research will be focused on potential natural foci of disease of these zoonoses. Results of the planned research will provide a more clear picture of distribution, genetic diversity, and pathogen potential of tick-borne microorganisms. It is expected to determine the competent reservoirs and to identify the natural enzootic pathogen cycles.