title: A distinctive clade B HIV type 1 is heterosexually transmitted in Trinidad and Tobago.
abstract: HIV-1 transmission worldwide is predominantly associated with heterosexual activity, and non-clade B viruses account for the most spread. The HIV-1 epidemic in Trinidad/Tobago and the Caribbean shares many features with such heterosexual epidemics, including a prominent role for coincident sexually transmitted diseases. This study evaluates the molecular epidemiology of HIV-1 in Trinidad/Tobago during a period when abrupt transition from homosexual to heterosexual transmission occurred in the absence of injecting drug use, concomitant with a rapid rise in HIV-1 prevalence in the heterosexual population. Of 31 viral isolates studied during 1987-1995, all cluster with subtype B reference strains. In the analysis of full env genes from 22 early seroconverters, the Trinidad isolates constitute a significant subcluster within the B subtype. The Trinidad V3 consensus sequence differs by a single amino acid from the prototype B V3 consensus and demonstrates stability over the decade of this study. In the majority of isolates, the V3 loop of env contains a signature threonine deletion that marks the lineage of the Trinidad HIV-1 clade B epidemic from pre-1984. No phenotypic features, including syncitium induction, neutralization profiles, and chemokine receptor usage, distinguish this virus population from other subtype B viruses. Thus, although the subtype B HIV-1 viruses being transmitted in Trinidad are genetically distinguishable from other subtype B viruses, this is probably the result of a strong founder effect in a geographically circumscribed population rather than genetic selection for heterosexual transmission. These results demonstrate that canonical clade B HIV-1 can generate a typical heterosexual epidemic.
authors.affiliation: Institute of Human Virology, University of Maryland, Baltimore, MD 21201, USA.
authors.forename: F R
authors.initials: FR
authors.lastname: Cleghorn
authors.forename: N
authors.initials: N
authors.lastname: Jack
authors.forename: J K
authors.initials: JK
authors.lastname: Carr
authors.forename: J
authors.initials: J
authors.lastname: Edwards
authors.forename: B
authors.initials: B
authors.lastname: Mahabir
authors.forename: A
authors.initials: A
authors.lastname: Sill
authors.forename: C B
authors.initials: CB
authors.lastname: McDanal
authors.forename: S M
authors.initials: SM
authors.lastname: Connolly
authors.forename: D
authors.initials: D
authors.lastname: Goodman
authors.forename: R Q
authors.initials: RQ
authors.lastname: Bennetts
authors.forename: T R
authors.initials: TR
authors.lastname: O'Brien
authors.forename: K J
authors.initials: KJ
authors.lastname: Weinhold
authors.forename: C
authors.initials: C
authors.lastname: Bartholomew
authors.forename: W A
authors.initials: WA
authors.lastname: Blattner
authors.forename: M L
authors.initials: ML
authors.lastname: Greenberg
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D017931:DNA Primers; D005260:Female; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000235:genetics; D015658:HIV Infections / Q000453:epidemiology / Q000635:transmission*; D015497:HIV-1 / Q000145:classification*; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D012725:Sexual Behavior; D013045:Species Specificity; D014300:Trinidad and Tobago / Q000453:epidemiology
chemical_list: D017931:DNA Primers; D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments