Article

The challenge of HIV-1 subtype diversity.

New England Journal of Medicine (Impact Factor: 54.42). 11/2008; 359(18):1965-6. DOI: 10.1056/NEJMc086373
Source: PubMed
0 Bookmarks
 · 
107 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The World Health Organization (WHO) recommends periodic surveillance of transmitted drug resistance (TDR) in communities where antiretroviral therapy (ART) has been scaled-up for greater than 3 years. We conducted a survey of TDR mutations among newly detected HIV infected antiretroviral (ARV)-naïve pregnant women. From May 2010 to March 2012, 38 ARV-naive pregnant women were recruited in three hospitals in Jos, Plateau state, north central Nigeria. Eligible subjects were recruited using a modified version of the binomial sequential sampling technique recommended by WHO. HIV-1 genotyping was performed and HIV-1 drug resistance mutations characterized according to WHO 2009 surveillance drug resistance mutation (SDRM) list. HIV subtypes were determined by phylogenetic analysis. The women's median age was 25.5 years; the median CD4+ cell counts was 317 cells/µl and median viral load of 16, 261copies/ml. Of the 38 samples tested, 34 (89%) were successfully genotyped. The SDRM rate was <5% for all ART drug classes, with 1/34 (2.9%) for NRTIs/NNRTIs and none for protease inhibitors 0/31 (0%). The specific SDRM detected were M41L for NRTI and G190A for NNRTI. HIV-1 subtypes detected were CRF02_AG (38.2%), G' (41.2%), G (14.7%), CRF06-CPX (2.9%) and a unique AG recombinant form (2.9%). The single ARV-native pregnant woman with SDRMS was infected with HIV-1 subtype G'. Access to ART has been available in the Jos area for over 8 years. The prevalence of TDR lower than 5%, suggests proper ART administration although continued surveillance is warranted.
    AIDS research and human retroviruses 10/2013; · 2.18 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Previous studies have attempted to explore the origin of the F1 subtype, but the precise origin of the Romanian and South American F1 variants remains controversial. As the F1 subtype is the most frequent non-B variant among Europeans residing in Italy, the aim of this study was to estimate its phylogeography in order to reconstruct its origin and route of dispersion. The phylogeographical analyses, which were made using the Bayesian Markov Chain Monte Carlo approach and BEAST software, revealed two significant clades: the first included all of the Romanian strains together with a few Italian and four African isolates; the second encompassed all of the South American sequences and the large majority of Italian variants. By putting the African reference sequences into two discrete groups based on specific countries, phylogeographic analysis indicated that the F1 epidemic originated in Cameroon/Democratic Republic of Congo in the early 1940s, and was exported to South America 10 years later. Subsequently, the F1 virus spread to Angola and, from there, was exported to Romania in the early 1960s. It reached Italy in the 1970s from South America and Romania. The South American and Romanian variants of F1 have different African countries of origin and different temporal spreads. The South American variant seems to be characterized by multiple introduction events, whereas the Romanian strain probably spread as a result of a single entry. Two different pathways from South America and Romania led the F1 variant to Italy in the 1970s. J. Med. Virol. © 2013 Wiley Periodicals, Inc.
    Journal of Medical Virology 10/2013; · 2.22 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Increased understanding of the genetic diversity of HIV-1 is challenging but important in the development of an effective vaccine. We aimed to describe the distribution of HIV-1 subtypes in northern Tanzania among women enrolled in studies preparing for HIV-1 prevention trials (hospitality facility-worker cohorts), and among men and women in an open cohort demographic surveillance system (Kisesa cohort). The polymerase encompassing partial reverse transcriptase was sequenced and phylogenetic analysis performed and subtype determined. Questionnaires documented demographic data. We examined factors associated with subtype using multinomial logistic regression, adjusted for study, age, and sex. Among 140 individuals (125 women and 15 men), subtype A1 predominated (54, 39%), followed by C (46, 33%), D (25, 18%) and unique recombinant forms (URFs) (15, 11%). There was weak evidence to suggest different subtype frequencies by study (for example, 18% URFs in the Kisesa cohort versus 5-9% in the hospitality facility-worker cohorts; adjusted relative-risk ratio (aRR) = 2.35 [95% CI 0.59,9.32]; global p = 0.09). Compared to men, women were less likely to have subtype D versus A (aRR = 0.12 [95% CI 0.02,0.76]; global p = 0.05). There was a trend to suggest lower relative risk of subtype D compared to A with older age (aRR = 0.44 [95% CI 0.23,0.85] per 10 years; global p = 0.05). We observed multiple subtypes, confirming the complex genetic diversity of HIV-1 strains circulating in northern Tanzania, and found some differences between cohorts and by age and sex. This has important implications for vaccine design and development, providing opportunity to determine vaccine efficacy in diverse HIV-1 strains.
    PLoS ONE 12/2013; 8(12):e81848. · 3.53 Impact Factor