The only cases outside the United States were in slaughter pigs on ships from the U.S. bound for Hawaii in 1947 and in pigs fed uncooked pork scraps from an American military base in Iceland in 1955.
美国以外的仅有的病例是，1947年美国用船运输到夏威夷的屠宰猪肉以及1955年在冰岛美军基地使用未煮熟的猪肉泔水饲喂的猪。