Molecular identification of Trichinella spp. in wild boar, and serological survey of high-risk populations in Iran

After half a century, Trichinella infection has been reported in humans following ingestion of wild boar meat hunted in Northern Iran. We have performed a cross-sectional study to evaluate the prevalence of Trichinella spp. infections in wild boar and prevalence of anti-Trichinella antibodies among at-risk individuals for the first time in Iran. Muscle and sera samples were collected from 79 wild boars and 364 at-risk individuals. Trichinella infection has been investigated by artificial digestion and molecular identification (in wild boar muscles) and by serology (in humans). Trichinella larvae were isolated from three wild boars (3.7%; 95% CI, 2.9-4.3). The isolated larvae were identified as T. britovi using CO1 and 5S rRNA gene primers amplification. The percent identity regarding to 5S rRNA gene (98.7-100%) and divergence (0-1.9%) further confirmed the isolates as T. britovi. Of the 364 participants, anti-Trichinella IgG were detected in 8 (2.2%; CI 95%, 1.9-2.4). Risk factors associated with Trichinella infection seropositivity in humans, were hunter being (OR, 13.5; 95% CI, 3.1-59.4; P = 0.003) and high consumption (more than 7 time in a year) of wild boar meat (OR, 17.5; 95% CI, 3.2-93.6; P < 0.001). In conclusion, results of this study emphasized that consumption of wild boar meat could be important source of human trichinellosis as a completely neglected infection disease in Iran. We suggest that the additional studies should be performed in different parts of Iran to further clarify the prevalence of trichinellosis in wild animals to guide the development of appropriate public health interventions.