Tropical sprue in American servicemen following return from Vietnam.

Moderately severe tropical sprue was diagnosed in two American servicemen 15 and 19 months after return from Vietnam. Intestinal parasites were not demonstrated, and clinical, laboratory, and jejunal histological abnormalities returned to normal following treatment with tetracycline and folic acid in one patient and folic acid alone in the other. Neither patient was anemic, although one had hypersegmented polymorphonuclear leukocytes and both had macrocytosis and megaloblastic bone marrows. In each of these patients, diagnosis was delayed because of the failure to consider tropical sprue in the differential diagnosis of diarrhea and weight loss. The findings in these patients indicate that individuals from nonendemic areas who reside in Vietnam are at risk of developing overt tropical sprue.