Phylodynamics of HIV-1 circulating recombinant forms 12_BF and 38_BF in Argentina and Uruguay

Retrovirology. 2010 Mar 22;7:22. doi: 10.1186/1742-4690-7-22.

Abstract

Background: Although HIV-1 CRF12_BF and CRF38_BF are two epidemiologically important recombinant lineages circulating in Argentina and Uruguay, little is known about their population dynamics.

Methods: A total of 120 "CRF12_BF-like" and 20 "CRF38_BF-like" pol recombinant sequences collected in Argentina and Uruguay from 1997 to 2009 were subjected to phylogenetic and Bayesian coalescent-based analyses to estimate evolutionary and demographic parameters.

Results: Phylogenetic analyses revealed that CRF12_BF viruses from Argentina and Uruguay constitute a single epidemic with multiple genetic exchanges among countries; whereas circulation of the CRF38_BF seems to be confined to Uruguay. The mean estimated substitution rate of CRF12_BF at pol gene (2.5 x 10-3 substitutions/site/year) was similar to that previously described for subtype B. According to our estimates, CRF12_BF and CRF38_BF originated at 1983 (1978-1988) and 1986 (1981-1990), respectively. After their emergence, the CRF12_BF and CRF38_BF epidemics seem to have experienced a period of rapid expansion with initial growth rates of around 1.2 year-1 and 0.9 year-1, respectively. Later, the rate of spread of these CRFs_BF seems to have slowed down since the mid-1990s.

Conclusions: Our results suggest that CRF12_BF and CRF38_BF viruses were generated during the 1980s, shortly after the estimated introduction of subtype F1 in South America (~1975-1980). After an initial phase of fast exponential expansion, the rate of spread of both CRFs_BF epidemics seems to have slowed down, thereby following a demographic pattern that resembles those previously reported for the HIV-1 epidemics in Brazil, USA, and Western Europe.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Argentina / epidemiology
  • Child
  • Child, Preschool
  • Cluster Analysis
  • Genotype
  • HIV Infections / epidemiology*
  • HIV Infections / virology*
  • HIV-1 / classification*
  • HIV-1 / genetics*
  • HIV-1 / isolation & purification
  • Humans
  • Molecular Epidemiology
  • Phylogeny
  • Point Mutation
  • Recombination, Genetic*
  • Sequence Analysis, DNA
  • Sequence Homology
  • Uruguay / epidemiology
  • Young Adult
  • pol Gene Products, Human Immunodeficiency Virus / genetics

Substances

  • pol Gene Products, Human Immunodeficiency Virus