The Occurrence of Freshwater Fish-Borne Zoonotic Helminths in Italy and Neighbouring Countries: A Systematic Review

In recent years, the consumption of fish products has surged in European countries, being an essential part of a healthy diet. Despite representing a small part of EU production, freshwater fisheries hold considerable significance for lake-dwelling populations and tourists seeking traditional dishes. This increased fish consumption has brought to light potential health risks associated with fish-borne zoonotic helminths (FBZHs), now acknowledged as global food-borne parasites. Fish-borne zoonotic helminths belong to various taxonomic groups, including nematodes (Anisakidae), trematodes (Opisthorchiidae and Heterophyidae), and cestodes (Diphyllobothriidae). More than 50 species of FBZH are known to cause human infections, derived from eating raw or undercooked aquatic foods containing viable parasites. Despite increased attention, FBZHs remain relatively neglected compared to other food-borne pathogens due to factors like chronic disease progression and under-diagnosis. This systematic review concentrates on the prevalence of six freshwater FBZHs (Clinostomum complanatum, Contracaecum rudolphii, Dibothriocephalus latus, Eustrongylides excisus, Opisthorchis felineus, and Pseudamphistomum truncatum) in Italy and neighbouring countries. The study explores the expansion of these parasites, analysing their biological and epidemiological aspects, and the factors that influence their proliferation, such as the increased cormorant population and the lake eutrophication phenomena. In summary, this research highlights the necessity for further research, the development of spatial databases, and the establishment of a unified European policy to effectively manage these multifaceted health concerns. It strongly advocates adopting a One-Health approach to address the growing incidence of parasitic zoonoses within the context of food safety in EU countries.