SELECTIVITY OF HUMAN T-LYMPHOTROPIC VIRUS TYPE-1 (HTLV-1) AND HTLV-2 INFECTION AMONG DIFFERENT POPULATIONS IN BRAZIL

A seroprevalence study for human T lymphotropic virus type-I (HTLV-1) and HTLV-2 was conducted in Sao Paulo, Brazil among 2,312 individuals that included following groups: 1, 148 volunteer blood donors, 3 7 pat ients with tropical spastic paraparcsis (TSP), 53 with lymphoprolifera tive disorders, 171 with a history of multiple blood transfusions, 268 human immunodeficiency virus type-1 (HIV- 1) seropositive subjects, a nd 635 Amazonian Indians. Antibodies to HTLV-1/2 were screened by enzy me-linked immunosorbent assay (ELISA) and confirmed by Western blot an d/or radioimmunoprecipitation. The differentiation of HTLV-1 and HTLV- 2 was achieved using a synthetic recombinant peptide (rgp46) ELISA. We confirmed the presence of HTLV-1 infection in Brazil, both in blood d onors (0.4%) and in patients exposed to blood transfusions (2.9%), as well as the occurrence of HTLV-I-associated TSP (11 patients, or 30% o f all TSP cases) and adult T cell leukemia/lymphoma (two cases, or 3.5 % of all hematologic malignancies). The HIV-1 infected individuals wer e shown to be coinfected (8.9%) with either HTLV-1 or HTLV-2. All HIV- 1 and HTLV-2 coinfected individuals were intravenous drug abusers. In addition, we also demonstrated the presence of HTLV-2 (4.7%), and HTLV -1/2 (0.8%) in tribes of Amazonian Indians who lived in the eastern Am azon basin (southeastern State of Para). The selectivity of these retr oviral infections in particular groups is emphasized, as well as the n eed for HTLV-1/2 screening of all blood donors in Brazil as a public h ealth measure.