Third outbreak of trichinellosis caused by consumption of horse meat in Italy.

The clinical and epidemiological aspects of the largest Italian outbreak of human trichinellosis which occurred in Northern Italy in August 1986 are reported. About 300 people who ate raw horse meat were involved. The clinical and biological aspects of 161 patients were studied. None died. The causal parasite, isolated from a patient, was identified through isoenzymatic typing as Trichinella nelsoni. Fever, oedema, myalgia and headache were the most common signs and symptoms. The Fluorescent Antibody Test (FAT) proved positive for 96 percent of the patients showing clinical manifestations. Essential laboratory data are reported.