Trichinosis acquired at sea--report of an outbreak.

In 1974, at least 13 persons acquired trichinosis aboard a luxury liner en route to Alaska. Epidemiologic investigation implicated ground beef served on the ship as the vehicle of transmission. The beef is thought to have been contaminated by pork which had previously been frozen, though presumably not under trichinacidal conditions. To our knowledge, this is the first report of trichinosis acquired at sea.