Trichinella spiralis a new alien parasite in Italy and the increased risk of infection for domestic and wild swine.

In Europe, Trichinella spiralis, the most dangerous species for humans of the genus Trichinella, has a patchy distribution with important foci in Eastern countries and Spain. This zoonotic pathogen was apparently not circulating among wild and domestic animals of Italy. In 2016, muscle larvae belonging to this nematode species were detected in a red fox (Vulpes vulpes) shot in the Piacenza province (Northern Italy). This parasite may have been introduced into northern Italy from eastern Europe by hunters, by a hunting dog, or by immigrants, who illegally carried infected meat in their personal baggage. In the same year, T. spiralis infected sausages illegally introduced by personal baggage into Italy from Romania, were inadequately disposed of in the garbage of a central Italian town. Even though these two episodes may not be connected in time and space, they represent an increased risk of infection for domestic and wild swine, which are highly susceptible to this pathogen. In these animals, T. spiralis shows a higher larval burden and a longer survival time than other Trichinella species. Since most of the Italian pig production plants are in northern Italy, the circulation of T. spiralis should be strictly monitored in wildlife living in these areas.