A distinctive clade B HIV type 1 is heterosexually transmitted in Trinidad and Tobago.
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.
Cleghorn
F R
FR
Institute of Human Virology, University of Maryland, Baltimore, MD 21201, USA.
Jack
N
N
Carr
J K
JK
Edwards
J
J
Mahabir
B
B
Sill
A
A
McDanal
C B
CB
Connolly
S M
SM
Goodman
D
D
Bennetts
R Q
RQ
O'Brien
T R
TR
Weinhold
K J
KJ
Bartholomew
C
C
Blattner
W A
WA
Greenberg
M L
ML
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
D017931:DNA Primers; D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments