Wildlife-domestic animals interface: “g-local” changes and risk for human health.

In Europe, climate change and policies in management of land and natural environments are transforming the interface between wildlife, domestic animals and humans, leading to an increased circulation of pathogens through it. In this scenario, ticks and tick-borne pathogens are of particular concern, as they are, respectively, key vectors and agents of emerging infectious diseases. Shared spaces such as hiking trails may represent a relevant transmission point. The rising incidence of tick-borne zoonoses and the complexity of their circulation highlights the need for comprehensive epidemiological research on wildlife-associated and vector-borne diseases, which has, in recent years, gathered increasing attention from the scientific community. An integrated surveillance approach should account for multiple host species (wild and domestic animals, humans, including the environment) and employ diverse data collection methodologies. Citizen science projects, for instance, have been proved valuable in monitoring the distribution of wildlife and tick populations, providing broad-scale ecological and epidemiological data that can integrate the ones produced by the scientific community. Meanwhile, camera traps offer high-resolution insights into wildlife dynamics, generating detailed data crucial for epidemiological modelling and assessing the host-pathogen relationship. Monitoring the temporal occupancy of wild ungulates (deer species and wild boar) and mesocarnivores, these datasets can improve predictions of tick abundance as well as the prevalence of tick-borne pathogens such as Piroplasmids, Anaplasmataceae, Borrelia burgdorferi or Rickettsiae of the Spotted Fever Group, especially when targeting single tick species and life stages like Ixodes ricinus nymphs, recognized as posing the highest transmission risk to humans. Also, they highlight the different impact that host species and external factors such as seasonality and the environment can have on ticks’ abundance and their pathogens’ prevalence. Despite an increasing awareness of the risk of exposure, individuals engaged in outdoor recreational or professional activities experience high rates of tick-borne infections, with prevalence values often comparable across different host groups such as game animals, hunting dogs, questing ticks and hunters. Given this widespread pathogen circulation, a holistic surveillance framework is necessary to integrate ecological, epidemiological, and citizen science data. This interdisciplinary approach will enhance predictive models, refine risk assessments, and support targeted public health interventions.