Landscape epidemiology of neglected tick-borne pathogens in central Europe

Studies of tick-borne diseases (TBDs) in Europe focus on pathogens with principal medical importance (e.g. Lyme disease and tick-borne encephalitis), but we have limited epidemiological information on the neglected pathogens, such as the members of the generaAnaplasma,Rickettsia,BabesiaandCandidatusNeoehrlichia mikurensis. Here, we integrated an extensive field sampling, laboratory analysis and GIS models to provide first publicly available information on pathogen diversity, prevalence and infection risk for four overlooked zoonotic TBDs in the Czech Republic. In addition, we assessed the effect of landscape variables on the abundance of questing ticks at different spatial scales and examined whether pathogen prevalence increased with tick density. Our data from 13,340 ticks collected in 142 municipalities showed thatA. phagocytophilum(MIR = 3.5%) andCa. Neoehrlichia mikurensis (MIR = 4.0%) pose geographically uneven risks with localized hotspots, whileRickettsia(MIR = 4.9%) andBabesia(MIR = 1.1%) had relatively homogeneous spatial distribution. Landscape variables had significant effect on tick abundance up to the scale of 1 km around the sampling sites. Questing ticks responded positively to landscape diversity and configuration, especially to forest patch density that strongly correlates with the amount of woodland-grassland ecotones. For all four pathogens, we found higher prevalence in places with higher densities of ticks, confirming the hypothesis that tick abundance amplifies the risk of TB infection. Our findings highlight the importance of landscape parameters for tick vectors, likely due to their effect on small vertebrates as reservoir hosts. Future studies should explicitly investigate the combined effect of landscape parameters and the composition and population dynamics of hosts on the host-vector-pathogen system.

Automated summary

Studies on tick-borne diseases in Europe mainly focus on pathogens like Lyme disease and tick-borne encephalitis, neglecting other pathogens like Anaplasma, Rickettsia, Babesia, and Candidatus Neoehrlichia mikurensis. Data from the Czech Republic shows uneven geographic distribution of certain pathogens, while landscape variables significantly influence tick abundance and pathogen prevalence.