Occurrence of Trichinella spp. in Grey Wolves and Red Foxes: Insights from Wild Mammal Surveillance in Emilia-Romagna (Italy).

Trichinella spp. are zoonotic nematodes with a global distribution, primarily maintained through wildlife reservoirs which complicates eradication efforts. In Europe, four species-T. spiralis, T. britovi, T. nativa, and T. pseudospiralis-circulate in wild carnivores and omnivores, with T. britovi and T. spiralis being the most prevalent in wild and domestic hosts. This study aimed to assess the presence and species distribution of Trichinella spp. in wild mammals. This study presents the results of five years of wildlife surveillance carried out within the long-standing monitoring program implemented in the Emilia-Romagna region, northern Italy, which has been in place since 2006. Between 2020 and 2024, a total of 104,338 wild mammals, including red foxes, wolves, and wild boar, were tested using the magnetic stirrer digestion method in accordance with EU regulations. A total of 12 animals (0.011%) were found to be infected with Trichinella larvae. Molecular identification of positive samples, performed at the European Union Reference Laboratory for Parasites, showed the presence of T. britovi in 11 animals, while one isolate remained unidentified. T. britovi was detected primarily in wolves and red foxes. No infections were identified in wild boar during the study period. Overall, the low prevalence observed confirms that Trichinella spp. infections in wildlife in Emilia-Romagna are sporadic but persistently present. Only T. britovi was detected, supporting its role as the predominant species in this area. These findings highlight the importance of long-term surveillance for early detection and risk assessment within a One Health framework.