First report of T. spiralis in a wolf in Italy: An increasing health concern?

Abstract

Trichinella spiralis is a zoonotic nematode parasite of worldwide distribution. It is present in Europe with important foci, particularly in Eastern countries and Spain. This species is generally associated with a domestic cycle that involves primarily pigs. It is best adapted for pigs but can also infect a wide range of other domestic, synanthropic, and wild mammals including carnivores, omnivores and scavengers. Before 2016, when T. spiralis larvae were detected in a red fox (Vulpes vulpes) in the Piacenza province (Emilia Romagna region, Northern Italy), this parasite had only been reported in Italy occasionally, being found in horses or pork products imported from Eastern Europe. We describe here the first isolation of T. spiralis in a wolf (Canis lupus) in the Lazio region, Central Italy. In the wolf specimen T. spiralis was identified in coinfection with Trichinella britovi, a species endemic in Italian wildlife. Among the Trichinella species, T. spiralis is the most frequently associated with human disease in Europe and is known to cause more severe symptoms than T. britovi. In light of wolf population expansion, the detection of T. spiralis in Central Italy implies new scenarios for the risk of human trichinellosis because of the high risk this species represents for domestic and wild pigs. Active monitoring of wildlife living in these areas is necessary to define the actual distribution of  this species and to detect its possible presence in other areas of the Italian peninsula.