Emerging pathogens and wildlife populations: shared infectious agents with implications for human and domestic animal health

The connection between wildlife populations with humans and domestic animals gained growing attention, especially following the Covid-19 pandemic. Although this recent mainstream awareness, the concepts at the basis of wildlife health surveillance (WHS) and in general, wildlife population health and ecosystem health and their relationship with human and livestock health, are well-established key points of veterinary, biology and ecology research. Despite their shared assumptions, the future trends of the most concerning emerging infectious diseases, of wildlife origin, and their potential spreading is still difficult to predict. Several interconnected drivers, both of natural and anthropogenic origin are involved, with global warming and globalization as some of the more impactful. The consciousness of this unpredictable events, from a certain extent, highlights the importance of an efficient WHS, as an essential tool to monitor continuously the health status of wildlife populations and their role in the emergence of pathogens. Currently, the most concerning emerging infectious diseases (EIDs) are managed through shared international plans. However, other infectious agents are still neglected, with few data available, or mainly studied in domestic populations, lacking an exhaustive knowledge of the wild counterparts. The present PhD thesis includes a collection of research papers on emerging infectious agents that impact human health (vector-borne infectious agents namely, tick-borne encephalitis virus, Rickettsiales, Bartonella spp., Coxiella spp., Borrelia burgdorferi complex, Usutu virus and West Nile virus) or domestic animal health (Porcine circovirus 2, Porcine circovirus 3, Canine circovirus, Avian circovirus; Carnivore protoparvovirus 1 and Amdoparvovirus genus). The outcomes reported gave new and updated insights of the above-mentioned EIDs. Although most of the research projects were conducted at a local level, and mainly in North-east Italy, the reported results and the diagnostic methods used are of relevance for WHS and the scientific community. The proved interconnection of several emerging pathogens between the different considered species, humans included, represents once again the importance of facing the topic of EIDs and multi-host pathogens in a One Health comprehensive perspective.