Control of trichinellosis by inspection and farm management practices

The prevention of human trichinellosis by proper meat inspection is a class ic example of successful veterinary public health measures. The microscopic methods which have been used for more than a century to test pigs for tric hinae were intended to prevent human disease. However, the value of these r elatively insensitive direct detection methods, including trichinoscopy and pooled sample digestion, was debated as soon as more sensitive indirect (s erological) methods became available. Two issues related to testing were di scussed. First, should public health authorities endeavour to prevent all i nfections of humans rather than simply prevent the occurrence of disease, a nd second, would epidemiological surveillance and monitoring of the pig pop ulation on farms not provide a better control system to prevent human infec tion. This latter issue is of particular importance for those countries in the world where human trichinellosis acquired from farmed animals is absent and examination of pigs at the abattoir only results in negative findings. In countries where domestic pig infections are virtually non-existent, mon itoring of Trichinella infection in wildlife could also contribute to under standing the infection pressure from nature to livestock. Trichinella-free pig farming is a feasible option for controlling this zoonosis, even in end emic areas. This approach provides an opportunity to combine good veterinar y practice, in order to prevent animal diseases, with the prevention of Tri chinella infection. All animals with access to the environment, or animals which are fed with potentially Trichinella-infected feed (swill, carcasses) will always constitute a public health threat, and must be inspected indiv idually at slaughter (swine, horses, wild boars). Finally, it is important to recognize that trichinellosis is a world-wide problem that needs continu ous public health attention. If no control system exists, for whatever reas on, the public should be educated not to consume improperly cooked meat. (C ) 2000 Elsevier Science B.V. All rights reserved.