Human T-cell lymphotropic virus type I (HTLV-I) seroepidemiology and risk factors in metropolitan Panamá.

Human T-cell lymphotropic virus type I (HTLV-I) infection and associated hematologic malignancies cluster in Japan, the Caribbean basin, and Central Africa. The authors believe that this study of HTLV-I seroepidemiology in the Republic of Panamá is the first detailed analytic study of environmental factors pertaining to HTLV-I infection in representative tropical populations. The study analyzed observational data concerning housing conditions, family composition, and demographic and behavioral attributes as risk factors for HTLV-I infection (HTLV-I antibody). The 745 study subjects were residents of representative households in Panamá City and Colón. Overall, 5% of sera had antibody against HTLV-I, detected by enzyme-linked immunosorbent assay and confirmed by competitive binding. Housing conditions, race, and socioeconomic factors were not associated with infection nor did infection cluster in families. Interview of 706 women enrolled in cervical cancer studies documented that female sexual experience (number of marriages or sexual partners) was associated with HTLV-I infection. These findings support the hypothesis that HTLV-I is not transmitted by casual contact but requires exposures involving exchange of bodily fluids.