HIV-1 genetic diversity and demographic characteristics in Bulgaria

PLoS One. 2019 May 28;14(5):e0217063. doi: 10.1371/journal.pone.0217063. eCollection 2019.

Abstract

HIV-1 strain diversity in Bulgaria is extensive and includes contributions from nearly all major subtypes and the Circulating Recombinant Forms (CRF): 01_AE, 02_AG, and 05_DF. Prior to this study, HIV-1 sequence information from Bulgaria has been based solely on the pro-RT gene, which represent less than 15% of the viral genome. To further characterize HIV-1 in Bulgaria, assess participant risk behaviors, and strengthen knowledge of circulating strains in the region, the study "Genetic Subtypes of HIV-1 in Bulgaria (RV240)" was conducted. This study employed the real time-PCR based Multi-region Hybridization Assay (MHA) B/non-B and HIV-1 sequencing to survey 215 of the approximately 1100 known HIV-1 infected Bulgarian adults (2008-2009) and determine if they were infected with subtype B HIV-1. The results indicated a subtype B prevalence of 40% and demonstrate the application of the MHA B/non-B in an area containing broad HIV-1 strain diversity. Within the assessed risk behaviors, the proportion of subtype B infection was greatest in men who have sex with men and lowest among those with drug use risk factors. During this study, 15 near full-length genomes and 22 envelope sequences were isolated from study participants. Phylogenetic analysis shows the presence of subtypes A1, B, C, F1, and G, CRF01_AE, CRF02_AG, CRF05_DF, and one unique recombinant form (URF). These sequences also show the presence of two strain groups containing participants with similar risk factors. Previous studies in African and Asian cohorts have shown that co-circulation of multiple subtypes can lead to viral recombination within super-infected individuals and the emergence of new URFs. The low prevalence of URFs in the presence of high subtype diversity in this study, may be the result of successful infection prevention and control programs. Continued epidemiological monitoring and support of infection prevention programs will help maintain control of the HIV-1 epidemic in Bulgaria.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Bulgaria / epidemiology
  • Female
  • Genetic Variation*
  • Genome, Viral
  • Geography
  • HIV Infections / epidemiology*
  • HIV Infections / virology*
  • HIV Seropositivity / epidemiology
  • HIV Seropositivity / virology
  • HIV-1 / genetics*
  • Homosexuality, Male
  • Humans
  • Male
  • Middle Aged
  • Molecular Epidemiology
  • Phylogeny
  • Prevalence
  • Real-Time Polymerase Chain Reaction
  • Regression Analysis
  • Risk Factors
  • Risk-Taking
  • Substance-Related Disorders / prevention & control

Grants and funding

Authors ESB, AOS, MB, SH, GHK, ABV, CTB, MLB, and ST received funding support in the form of money paid to the institution by cooperative agreement (W81XWH-07-2-0067) between the Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., and the U.S. Department of Defense (DOD). Additionally, author GHK is currently a paid employee of GlaxoSmithKline (GSK) Vaccines and receives financial support in the form of a salary. However, his contribution to the research reported on in this paper took place prior to this commercial affiliation. The specific roles of this author are articulated in the 'author contributions' section. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The material has been reviewed by the Walter Reed Army Institute of Research and there is no objection to its presentation and/or publication. The Walter Reed Army Institute of Research Institutional Research Board human use protocol #W1424 (RV240), ‘‘Genetic Subtypes of HIV-1 in Bulgaria from 2008-2009’’ was funded through the United States Military HIV Research Program (the Walter Reed Army Institute of Research and the Henry M. Jackson Foundation for the Advancement of Military Medicine).