Imported echinococcosis in southern California

A retrospective chart review conducted at two teaching hospitals in Los Angeles County identified 28 patients with infection due to Echinococcus granulosus diagnosed by positive echinococcal serology and/or tissue biopsy between January 1981 and December 1990. Of these patients, 25 (89%) were foreign born and 19 (68%) were immigrants from the Middle East or central Asia. Only 12 of 22 immigrants questioned about epidemiologic risk factors described a history of rural residence or direct exposure to dogs in their native country. Single cysts of liver, lung, and soft tissue were present in six of 28 patients; multiple cysts in the 22 remaining patients were exclusively hepatic in 13 patients, exclusively pulmonary in two patients, and involved mixed sites including liver, lung, abdomen, central nervous system, and bone in seven patients. Natives of middle eastern countries currently constitute a major risk group for imported infection due to E. granulosus in the United States. Since their epidemiologic risk factors may be absent and clinical presentations varied, a high index of suspicion for echinococcosis is warranted in this population based solely on the presence of a cystic mass in liver, lung, or another organ site.