From reservoirs to ecological integrators: the role of European Apodemus spp. in vector-borne zoonotic pathogens

Rodents of the genus Apodemus are among the most widespread and abundant small mammals in Europe and play a central role in the ecology of numerous zoonotic pathogens. Owing to their ecological plasticity, high population densities, and frequent infestation by arthropod vectors, Apodemus species contribute to the maintenance and transmission of a diverse array of bacterial, viral, and protozoan agents of public health concern. This narrative review synthesises current knowledge on vector-borne pathogens associated with European Apodemus spp. and highlights marked heterogeneity in species-specific epidemiological roles across pathogens. We highlight marked heterogeneity in the epidemiological roles of Apodemus spp. across pathogens. While they function as confirmed reservoir hosts for some agents, particularly certain Borrelia genospecies and Neoehrlichia mikurensis, their contribution to other transmission cycles is ecotype-dependent, indirect, or context-specific. Infection dynamics are shaped by host demography, population density, community composition, habitat configuration, and climatic variability, which together modulate vector abundance, host-vector contact rates, and environmental persistence. Importantly, infection prevalence alone does not equate to reservoir competence; instead, pathogen-specific life histories and ecological context determine the extent to which Apodemus spp. amplify or bridge transmission. Landscape structure, forest cover, and temperature-related variables emerge as key large-scale predictors of tick-borne pathogen incidence, linking rodent ecology to human disease risk. Urbanisation and land-use change further reorganise host-vector networks, creating novel interfaces for spillover. By integrating multi-pathogen evidence across ecological scales, this review underscores the importance of adopting a One Health perspective that considers rodent ecology, vector biology, and environmental change in concert. Understanding the context-dependent role of Apodemus spp. is essential for anticipating future zoonotic risk under ongoing climatic and landscape transformation.