Trichinellosis in wild and domestic pigs and public health: a Serbian perspective

Abstract

Among a large number of susceptible animal species, the domestic pig is the most important source of human Trichinella infection worldwide. Trichinellosis is commonly defined by two cycles; `domestic' (in pigs on-farm) and `sylvatic' (in wildlife). Under conditions on industrial farms (particularly indoor) with good hygienic practices and efficient management including biosecurity, combined with effective governmental/veterinary services, Trichinella transmission via the domestic cycle is unlikely. In countries effectively implementing these strategies and with officially recognised negligible risk of Trichinella in domestic pigs, testing for this parasite at meat inspection is no longer mandatory for slaughter pigs reared in integrated production. In other countries, testing for Trichinella of slaughtered pigs is a very important component of the control system. Under conditions on small farms with pigs having access to the outdoors and where control measures are poorly implemented, or are lacking, the domestic cycle can play a very important role in trichinellosis transmission. This possibility is further enhanced where socio-economic and political problems temporarily diminish the efficacy of the governmental/veterinary services. Additionally, the practice of making uncooked products from meats of uninspected domestic and/or wild pigs at home represents a major risk for human infection. The risk of further spreading trichinellosis is additionally exacerbated by increased globalisation in modern times, including increased movements of livestock, food and people. Traditional farming practices facilitating a mixture of domestic and sylvatic cycles of Trichinella need to be modified/improved so to ensure the separation of the cycles. Furthermore, hunters need to be educated to avoid leaving animal carcasses or their entrails in the field because this increases the probability of transmission to new hosts. Also, the farmers, the hunters and the consumers should be educated to freeze pork (including meat from wild boars) before its further home-processing into products, or to cook the product before consumption, or both, aimed at the larvae inactivation.