First Report of Trichinella spiralis in Free-Living Invasive American Mink (Neovison vison) in Lithuania

The genus Trichinella comprises zoonotic nematodes infecting a wide range of carnivorous and omnivorous animals, including humans. Infection occurs through the consumption of raw or undercooked meat containing viable Trichinella larvae. Among the species within this genus, Trichinella spiralis is considered one of the most epidemiologically important due to its high reproductive capacity and its frequent association with infections in domestic animals and humans. In this study, muscle samples from 18 invasive American minks (Neovison vison) were examined for Trichinella larvae using the magnetic stirrer method. Species identification was performed via multiplex polymerase chain reaction (PCR), while the internal transcribed spacer 1 (ITS1) region was amplified to evaluate the intraspecific genetic variability. Trichinella larvae were detected in one of the 18 (5.6%) animals investigated, and all isolates were identified as T. spiralis. Ten ITS1 sequences obtained from individual larvae were 100% identical. Network and principal coordinate analyses revealed that the sequences clustered by geographic origin rather than host species and were more related to isolates from domestic pigs than to wildlife animals. These findings provide the first evidence of T. spiralis in American minks in Baltic and Scandinavian countries and contribute to a better understanding of the epidemiology of trichinellosis in the region.