Temporal changes in rodent- and tick-borne diseases in Europe: how are they linked?

Generalist rodent species, such as Apodemus flavicollis and Myodes glareolus, play an important role as reservoirs of a number of directly transmitted zoonotic pathogens, such as hantaviruses and other rodent-borne pathogens. At the same time, these species are also reservoirs of emerging tick borne diseases, such as Tick borne encephalitis and Lyme borreliosis. In general, rodentborne and tick -borne diseases cannot be easily controlled with the massive use of rodenticide, acaricide or large-scale animal culling. Instead, preventing and reducing the exposure of humans to such pathogens and their vectors in hot spots of infection during periods when these hazards are higher, is a more realistic and sustainable option. However, these recommendations are only possible if such hazards are predictable. The incidence of rodent and tick borne diseases varies spatially and temporally in European citizens, and therefore understanding the drivers of such variations is relevant for identifying early warning predictors of the changing risk. In particular, understanding the consequences of rodent fluctuations not only on directly transmitted pathogens but also on tick -borne infection risk can provide a framework for prevention of multiple pathogens. Therefore, we established a joint multiannual monitoring survey in three European countries (Italy, Slovakia and Finland). Collection of questing ticks and rodents were carried out at our study sites for four years. Serological and molecular investigations were carried out both on rodents and ticks collected either from vegetation and directly from the hosts to identify their infectious status and prevalence of infection for several pathogens. Findings and criteria for selection of early warning predictors will be presented and discussed.