Surveillance of Zoonotic Pathogens in Small Mammals Across Forests With Different Levels of Anthropization in Eastern...

The emergence of infectious diseases associated with land-use changes is well-documented. However, the presence and dynamics of zoonotic pathogens in small mammals within European forests, whether from rural development or urban greening, remain underexplored. To describe zoonotic hazards in these ecosystems, and to assess the influence of biotic and abiotic factors on their distribution, we analyzed 1549 individuals from 18 small mammal species sampled across forest types representing different levels of anthropization using both targeted and broad-spectrum serological and molecular methods. We detected nine bacteria and five Apicomplexa that are potentially pathogenic to humans. Zoonotic pathogen richness and community composition varied significantly across host species, sites, and sampling periods. Richness was lower in forested urban parks, possibly due to the absence of vectors or intermediate hosts within cities. It was higher in urban adapter species, even within a given forested habitat, emphasizing the important role of specific life-history traits. Pathogen community structure was shaped by forest anthropization and host ecology, with marked differences between urban and rural forested environments and between urban adapter and dweller species within forested urban parks. The seroprevalence of key pathogens (e.g., Bartonella, Orthopoxvirus, Neoehrlichia mikurensis, and Sarcocystidae) showed spatial, temporal, and host-specific variation. Epidemiological differences between sites often exceeded those between habitat types, in particular when comparing protected and managed forests, highlighting the importance of local ecological context. Nevertheless, some patterns reflected the influence of forest anthropization and species urban adaptation strategies for certain zoonotic agents. High anthropization in forests was associated with elevated Bartonella prevalence, driven by urban-adapter species rather than forest dwellers, emphasizing local ecological interactions between hosts and pathogens. Besides, higher levels of Orthopoxvirus seroprevalence were associated with adapter species in protected forests where they might be more abundant. Altogether, these findings underscore the need for integrated and multipathogen wildlife surveillance to anticipate and mitigate disease risks at the human-environment-animal interface.