Strongyloidiasis associated with human T-cell lymphotropic virus type I infection in a nonendemic area.

Concomitant strongyloidiasis and human T-cell lymphotropic virus type I (HTLV-I) infection has been reported from areas in Japan where both organisms are endemic. We present four cases of concomitant infection with these organisms from an area that is not endemic for Strongyloides stercoralis. Three of the four patients had adult T-cell leukemia, an aggressive neoplasm resulting from HTLV-I infection, while the other was an asymptomatic carrier of HTLV-I. Three of the patients had spent their childhoods in an endemic location for both organisms, suggesting an initial infection at that time. Three patients were symptomatic from their parasitism. We conclude that strongyloidiasis may be found in nonendemic locations in patients with either adult T-cell leukemia or an asymptomatic HTLV-I carrier state. Whether infestation with this parasite contributes to the leukemogenesis of HTLV-I, as postulated by others, cannot at this time be determined.