Occurrence of Trichinella Species in Wild Boar (Sus scrofa) Populations Across Bulgaria

Trichinellosis is a natural-focal helminthic zoonosis that affects the skeletal muscle tissue of carnivorous and omnivorous wild and domestic animals. In Europe, four prevalent species belonging to the genus <i>Trichinella</i> have been identified: <i>T. spiralis</i>, <i>T. britovi</i>, <i>T. nativa</i> and <i>T. pseudospiralis</i>. The aim of this study was to identify the <i>Trichinella</i> species circulating in wild boar populations in Bulgaria, and to evaluate their prevalence. The research covered five hunting seasons, from October 2020 to February 2025. A total of 43,228 wild boar carcasses were examined using artificial digestion, and 597 tested positive, corresponding to a prevalence of 1.5%. The <i>Trichinella</i> isolates were identified at the species level by multiplex PCR at the European Union Reference Laboratory for Parasites in Rome, Italy. Among the samples suitable for molecular identification, <i>Trichinella britovi</i> was the only species detected in wild boar in Bulgaria during the study period, although other <i>Trichinella</i> species, including <i>T. spiralis</i> and <i>T. pseudospiralis</i>, have occasionally been reported in this host in earlier investigations. Geographical distribution analysis showed that most infected wild boar originated from southern part of the country.