Trichinella infection in culled wild boar (Sus scrofa) from El Palmar National Park, Argentina, and exposure risk in humans and dogs consuming wild boar meat

Abstract

Trichinellosis is a food-borne disease caused by ingestion of raw or undercooked meat containing Trichinella larvae. Consumption of wild boar (Sus scrofa) meat represents an important source of human trichinellosis worldwide. In El Palmar National Park (EPNP), Argentina, alien invasive wild boar are controlled and the meat from culled animals is released for public consumption following on-site artificial digestion (AD) testing. Meat trimmings and offal from the control program are often used as food for dogs. In this study, we evaluated infection and exposure to Trichinella spp. in wild boar from EPNP, as well as exposure to Trichinella spp. and associated risk factors in dogs and human consumers of wild boar meat. Trichinella spp. larvae were detected in muscle samples from 5/49 wild boar by AD (10.2% ± CI95% 3.8-23), with an average burden of 0.24 lpg (range 0.06 - 0.95 lpg). Anti-Trichinella antibodies were not detected in wild boar serum samples (n=42). In dogs, 12/34 were seropositive to Trichinella spp. (35.29% ± CI95% 20.3-53.5). IgG antibodies were not detected in human serum samples (n=63). Our results reveal the presence, albeit at low prevalence, of Trichinella spp. in wild boar and exposure in dogs fed game offal. These findings suggest that the low prevalence and parasitic load in wild boar, together with the best practices applied by EPNP culling program personnel, contribute to keeping the risk of infection in people low. However, the dog results highlight that the parasite is circulating in the area and therefore the risk of infection is not negligible. We recommend the implementation of an animal surveillance strategy in order to monitor the evolution of this zoonosis in the study area.