Dissemination of nonpandemic Caribbean HIV-1 subtype B clades in Latin America.

Objective: To estimate the prevalence of the HIV-1 subtype B pandemic (BPANDEMIC) and Caribbean (BCAR) clades in Latin America and to reconstruct the spatiotemporal dynamics of dissemination of the BCAR clades in the region.

Design: A total of 7654 HIV-1 subtype B pol sequences collected from 18 different Latin American countries between 1989 and 2011 were analyzed together with subtype B reference sequences representative of the BPANDEMIC (US/France = 300) and the BCAR (Caribbean = 279, Panama = 37) clades.

Methods: Phylogeographic and evolutionary parameters were estimated from sequence data using maximum likelihood and Bayesian coalescent-based methods.

Results: Nonpandemic BCAR strains were probably disseminated from the Caribbean islands of Hispaniola and Trinidad and Tobago into Latin America since the early 1970s. The BCAR strains reached nearly all countries from Latin America here analyzed and in some of them were spread locally, although their overall prevalence in the region is low. The BPANDEMIC clade comprises more than 90% of subtype B infections in most countries analyzed, with exception of Suriname, French Guyana and probably Guyana, where both BPANDEMIC and BCAR clades seem to circulate at a similar prevalence.

Conclusion: This study demonstrates that nonpandemic subtype B lineages of Caribbean origin have been disseminated into Latin America shortly after the estimated introduction of subtype B in the continent. Despite their early dissemination, the BCAR strains account for a minor fraction of current HIV-1 subtype B infections in the region that are mainly driven by spreading of the globally disseminated BPANDEMIC clade.