Globin haplotypes of human T-cell lymphotropic virus type I-infected individuals in Salvador Bahia Brazil suggest a post-Columbian African origin of this virus.

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. sA-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 (294%) 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 sA-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. (authors)