Rediscovery of Trichinella spiralis in red foxes ( Vulpes vulpes) in Ireland after 30 years of oblivion

Abstract

Objective. To determine whether or not Ireland can be considered as Trichinella-free, after more than 30 years of no reported infections in domestic and sylvatic animals and in humans. Methods. Samples of muscle tissue from the tongue, masseter, and foreleg of red foxes ( Vulpes vulpes) were subjected to artificial digestion and to multiplex-PCR analysis for identifying Trichinella larvae at the species level. Results. Four of 454 examined foxes were positive for larvae (overall prevalence 0.9%). The positive foxes had been collected in Donegal County (one fox; prevalence of 7.7%), Cork County (two foxes; 3.1%), and Waterford County (one fox; 4.2%). All larvae were identified as Trichinella spiralis. Conclusions. The detection of Trichinella-positive foxes in Ireland is an example of how the lack of infections among domestic animals and humans does not suffice for establishing Trichinella-free status. The results also confirm that the sylvatic cycle can last for tens of years, independently of the existence of a domestic cycle.