Trichinosis is an infection that occurs after eating contaminated meat (usually pork - also includes other animals such as rats, bears, cats, dogs, foxes, opossums, walrus and raccoons) without proper preparation. The larvae of the small roundworm, Trichinella spiralis invade the muscle of the pig. Human infection occurs by eating the infected pork, usually as raw or undercooked sausage or meat. The larvae mature in the human intestine and enter the bloodstream, invading many organs.
Trichinosis infects both man and animals, and can be fatal. Man usually becomes infected by eating uncooked or inadequately cooked infected meat (generally pork), in which the immature Trichinella spiralis is encysted. The disease has been observed in more than 100 species of domestic and wild animals, including herbivores, carnivores and rodents, but is most common in swine.
Trichinosis occurs worldwide, except for many of the Pacific islands. The number of human cases of trichinosis worldwide is about 30 million; almost all are in the USA, with minor outbreaks in Europe, Canada, Chile and Australia.