Localization of Trichinella spiralis in muscles of commercial and parasitologic interest in pork.

Trichinellosis is widespread around the world with different representatives of the genus Trichinella found in almost every continent. In Argentina the main source of transmission for the disease to humans is pig meat infected with Trichinella spiralis. The object of this work was to determine the distribution of Trichinella larvae in fresh meat cuts which are sold for human consumption and in the muscles traditionally used for the disease diagnosis at meat-packing plants. Cranial muscles to the last rib showed more Trichinella spiralis larvae than those with a caudal location (p < 0.01). No significant differences were found (p > 0.05) between bilateral left and right muscles. Significant larval concentrations were found in the neck muscles, even in carcasses with a low parasitic load; these muscles are used to prepare cold meats (boston butt). Commercial cuts of meat had a substantial larval burdens in animals experimentally infected with 500 to 5,000 Trichinella spiralis larvae, with parasite burdens similar to infection levels in muscles evaluated at the meat packing plant.