RESUMO
The city of Salvador, Bahia, Brazil, has sociodemographic characteristics similar to some African cities. Up to now, it has had the highest prevalence of human T-cell lymphotropic virus type I (HTLV-I) infection (1.74%) in the country. To investigate which strains of HTLV-I are circulating in Salvador, we studied isolates from 82 patients infected with HTLV-I: 19 from the general population, 21 from pregnant women, 16 from intravenous drug users, and 26 from patients and their family attending a neurologic clinic. Phylogenetic analysis from part of the LTR fragments showed that most of these isolates belonged to the Transcontinental subgroup of the Cosmopolitan subtype (HTLV-Ia). Only one sample from a pregnant woman was closely related to the Japanese subgroup, suggesting recent introduction of a Japanese HTLV-I lineage into Salvador. betaA-Globin haplotypes were examined in 34 infected individuals and found to be atypical, confirming the racial heterogeneity of this population. A total of 20 chromosomes were characterized as Central African Republic (CAR) haplotype (29.4%), 31 (45.6%) were characterized as Benin (BEN) haplotype, and 17 (25%) were characterized as Senegal (SEN) haplotype. Five patients' genotypes (14.7%) were CAR/CAR; 10 (29,4%), BEN/BEN; 9 (26.5%), CAR/BEN; 2 (5.9%), BEN/SEN; and 7 (20.6%), SEN/SEN. One patient's genotype (2.9%) was CAR/SEN. The betaA-globin haplotype distribution in Salvador is unusual compared with other Brazilian states. Our data support the hypothesis of multiple post-Columbian introductions of African HTLV-Ia strains in Salvador, Bahia, Brazil.