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.