Trophic cascades and pathogen transmission in an ever changing environment: the case study of Echinococcus multilocularis

Parasites with complex predator-prey life cycles need several factors for their establishment and expansion in new areas, especially in an ever-changing world under climate change and anthropic impact. This is the case of Echinococcus multilocularis, a zoonotic cestode with a sylvatic life cycle, involving wild canids and arvicolines as main definitive and intermediate hosts, respectively, and is also the aetiological agent of alveolar echinococcosis, which is the third worldwide most impacting food-borne zoonosis. Despite decades of research, there is still uncertainty on the reasons behind the distinct pattern of parasite increasing expansion throughout Europe. I systematically reviewed the frequency of intermediate host species in the diet of red foxes and compared with the parasite prevalence rate in red foxes from different European regions. I also evaluated the usefulness of genetic microsatellite variability as a proxy of the ongoing scenario. Then, I focused my research to assess the parasite occurrence in different host species from two separate Italian study areas. This thesis helps to describe the dynamic scenarios throughout Europe, mainly in the Italian edge, partially filling the existing knowledge gaps. These results highlight the need of further research in marginal regions and life cycle aspects, and represent a valid update for stakeholders. However, the lack of a standardised approach is the main limit to a correct and complete perspective.