In late February 1998, an outbreak of human trichinellosis occurred in the town of Piacenza (northern Italy) among 92 persons who had eaten raw horsemeat. The source of infection was a horse imported to the abattoir of Brescia one month previously. Although the horse had been found to be positive for trichinellosis upon routine examination, the head of an uninfected horse was exchanged with the head of the infected animal, which was mistakenly placed on the market.