High Prevalence and Onward Transmission of Non-Pandemic HIV-1 Subtype B Clades in Northern and Northeastern Brazilian Regions

PLoS One. 2016 Sep 7;11(9):e0162112. doi: 10.1371/journal.pone.0162112. eCollection 2016.

Abstract

The Human immunodeficiency virus type-1 (HIV-1) epidemic in Brazil is mainly driven by the subtype B pandemic lineage (BPANDEMIC), while Caribbean non-pandemic subtype B clades (BCAR) seem to account for a very low fraction of HIV-infections in this country. The molecular characteristics of the HIV-1 subtype B strains disseminated in the Northern and Northeastern Brazilian regions, however, have not been explored so far. In this study, we estimate the prevalence of the HIV-1 BPANDEMIC and BCAR clades across different Brazilian regions and we reconstruct the spatiotemporal dynamics of dissemination of the major Brazilian BCAR clades. A total of 2,682 HIV-1 subtype B pol sequences collected from 21 different Brazilian states from the five country regions between 1998 and 2013 were analyzed. Maximum Likelihood phylogenetic analyses revealed that the BCAR strains reached 16 out 21 Brazilian states here analyzed. The BCAR clades comprise a low fraction (<10%) of subtype B infections in most Brazilian states analyzed, with exception of Roraima (41%), Amazonas (14%) and Maranhão (14%). Bayesian phylogeographic analyses indicate that BCAR strains originally from the Hispaniola and Trinidad and Tobago were introduced at multiple times into different states from all Brazilian regions and a few of those strains, probably introduced into Roraima, Maranhão and São Paulo between the late 1970s and the early 1980s, established secondary outbreaks in the Brazilian population. These results support that the HIV-1 subtype B epidemics in some Brazilian states from the Northern and Northeastern regions display a unique molecular pattern characterized by the high prevalence of BCAR lineages, which probably reflects a strong epidemiological link with the HIV-1 epidemics in the Caribbean region.

MeSH terms

  • Bayes Theorem
  • Brazil / epidemiology
  • Caribbean Region
  • HIV Infections / epidemiology*
  • HIV Infections / transmission*
  • HIV Infections / virology
  • HIV-1 / physiology*
  • Humans
  • Likelihood Functions
  • Pandemics*
  • Phylogeny
  • Prevalence
  • Spatio-Temporal Analysis

Grants and funding

GB was supported by Public Health Service grants E-26/110.439/2014 from the “Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro” (FAPERJ) and 472896/2012-1 from the “Conselho Nacional de Desenvolvimento Científico e Tecnológico” (CNPq). FD was funded by a fellowship from Instituto Oswaldo Cruz -FIOCRUZ. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.