Seroepidemiology of human T-cell lymphotropic virus type I/II in northeastern Brazil.

We investigated the prevalence of human T-lymphotropic virus I/II (HTLV-I/II) infection in Bahia, a state in Northeastern Brazil. Healthy individuals (n = 327) and patients (n = 337) with a variety of diseases were screened for antibodies to HTLV-I/II using an enzyme immunoassay and Western blot. The overall prevalence among healthy subjects was 1.8% (six of 327); among patients it was 18.4% (62 of 337). Patients with AIDS had the highest prevalence of HTLV-I/II infection, 22.7% (20/88), followed by randomly selected patients from an infectious disease hospital, 19.4% (25 of 129), and tuberculosis patients, 11.1% (10 of 90). Four of 14 patients with myelopathy and three of 16 patients with lymphoid leukemia or lymphoma were seropositive for HTLV-I/II. Sixty-three of 68 HTLV-I/II-positive specimens were then typed: 53 patients were HTLV-I positive, three patients were HTLV-II positive, and in seven patients the assay could not distinguish infection by HTLV-I or II. The finding among HIV-seropositive intravenous drug users in Bahia of coinfection with HTLV-I is contrasted with reports from other areas in which dual infection occurs with HTLV-II. Although high prevalence of HTLV-I infection was found in Bahia, the extent and clinical manifestations of HTLV-I/II infection in Brazil remains imprecisely defined, and further studies are needed.