First finding of Trichinella pseudospiralis in two tawny owls (Strix aluco) from Sweden

The worldwide distribution of Trichinella pseudospiralis, the first discovered non-encapsulated Trichinella species infecting both mammals and avian hosts, has been suggested to be attributed to bird migration. At present, the knowledge on the role of carnivorous avian species as a reservoir hosts in Europe is still limited. Thus, the aim of this research was to screen for T. pseudospiralis in raptorial, carrion-feeding, and scavenging birds in Sweden and Slovakia, where the parasite has been previously documented in wildlife. In total, 212 pectoral muscle samples of carnivorous birds from Slovakia (n = 153) and Sweden (n = 59) were examined for the presence of Trichinella larvae using standard artificial digestion method. Out of 12 Accipitridae species, 4 Falconidae species, 2 Strigidae species, 1 Tytonidae species, and 4 Corvidae species examined within our study, muscle larvae were found in two non-migratory tawny owls (Strix aluco) from one geographical region of Sweden. Histological and molecular methods confirmed the presence of T. pseudospiralis. This is the first report of this parasite in an avian species in Sweden and the second report in European birds.