ABSTRACT
Kazakhstan experienced the start of the HIV-1 outbreak among intravenous drug users (IDUs) in 1997. To characterize genetically HIV-1 strains circulating in this country, peripheral blood mononuclear cells (PBMCs) DNA samples (1999-2002) derived from HIV-infected IDUs and their sexual partners in Pavlodar (n = 19), Shymkent (n = 6), and Qaraghandy (n = 18) regions were analyzed by the gag/env heteroduplex mobility assay (HMA). The 366-bp proviral env gene fragments encoding the gp120 C2-V3 region obtained from 16 individuals were sequenced. The results of HMA revealed that all 43 HIV-1 strains studied belonged to gag/env subtype A. The nucleotide sequence analysis showed a marked genetic homogeneity with the mean genetic distance being 3.63 +/- 2.39 (range 0.00-12.13). The mean genetic distance between each sequence within the Kazakhstan set and the East-European IDU subtype A consensus was 2.94 +/- 1.92 (range 0.79-8.48). The data presented thus confirm the spreading of the same IDU subtype A virus in the former Soviet Union.
Subject(s)
Disease Outbreaks , HIV Infections/epidemiology , HIV-1/classification , HIV-1/genetics , Substance Abuse, Intravenous/complications , Adult , Amino Acid Sequence , Female , HIV Envelope Protein gp120/genetics , HIV Infections/virology , Heteroduplex Analysis , Humans , Kazakhstan/epidemiology , Male , Molecular Sequence Data , Phylogeny , Sequence Analysis, DNAABSTRACT
To characterize polymorphisms of the subtype A protease in the former Soviet Union, proviral DNA samples were obtained, with informed consent, from 119 human immunodeficiency virus type 1 (HIV-1)-positive untreated injecting drug users (IDUs) from 16 regions. All individuals studied have never been treated with antiretroviral drugs. The isolates were defined as IDU-A (n = 115) and CRF03_AB (n = 4) by using gag/env HMA/sequencing. The pro region was analyzed by using sequencing and original HIV-ProteaseChip hybridization technology. The mean of pairwise nucleotide distance between 27 pro sequences (23 IDU-A and 4 CRF03_AB) was low (1.38 +/- 0.79; range, 0.00 to 3.23). All sequences contained no primary resistance mutations. However, 13 of 23 (56.5%) subtype A isolates bore the V77I substitution known as the secondary protease mutation. V77I was associated with two synonymous substitutions in triplets 31 and 78, suggesting that all V77I-bearing viruses evolved from a single source in 1997. Hybridization analysis showed that 55 of 115 (47.8%) HIV-1 isolates contained V77I, but this variant was not found in any of 31 DNA samples taken from regions, where the HIV-1 epidemic among IDUs started earlier 1997, as well as in any of four CRF03_AB isolates. The results of analysis of 12 additional samples derived from epidemiologically linked subjects showed that in all four epidemiological clusters the genotype of the donor and the recipients was the same irrespective of the route of transmission. This finding demonstrates the transmission of the V77I mutant variant, which is spreading rapidly within the circulating viral pool in Russia and Kazakhstan. The continued molecular epidemiological and virological monitoring of HIV-1 worldwide thus remains of great importance.
Subject(s)
Genetic Variation , HIV Infections/epidemiology , HIV Protease/genetics , Substance Abuse, Intravenous/complications , Adolescent , Adult , Amino Acid Sequence , Base Sequence , Drug Resistance, Viral/genetics , Europe, Eastern/epidemiology , Female , HIV Infections/virology , HIV Protease/chemistry , HIV-1/classification , HIV-1/drug effects , HIV-1/genetics , Humans , Male , Molecular Sequence Data , Mutation , Oligonucleotide Array Sequence Analysis , Phylogeny , Protease Inhibitors/pharmacologyABSTRACT
During the period 1996-1997, three highly homogeneous variants of HIV-1 were identified, circulating among injecting drug users (IDUs) in the former Soviet Union republics. One of these belonged to HIV-1 genetic subtype A (IDU-A), another belonged to HIV-1 genetic subtype B (IDU-B) and the third was a recombinant between the first two variants (CRF03_AB). However, since 1997, the HIV-1 epidemic has affected an increasing number of geographic regions in Russia. This study was undertaken to survey the prevailing genetic variants and to estimate the current proportions of these three HIV-1 genetic subtypes in Russia. Blood samples were taken in 1999-2003 from 1090 HIV-infected individuals and analysed by gag/env HMA. The IDU-A variant was found to be the majority variant (89.7-100%) in 44 of 45 regions of the Russian Federation studied. The IDU-A variant was also found to spreading rapidly through heterosexual transmission in 1999-2003 (30/34, 88%). CRF03_AB predominates in the Kaliningrad region only (28/29, 96.6%). The IDU-B variant is currently of minor importance in the IDU epidemic but other European subtype B variants predominate among men having sex with men (18/18, 100%). Sequence analysis of the env V3 encoding regions derived from HIV-1 infected individuals in Yekaterinburg (the main centre of the HIV-1 epidemic in Russia in 2002-2003) showed that the IDU-A variant is still highly homogeneous. The mean pairwise nucleotide distance (n = 9) was 2.89 +/- 1.14 (range 1.36-6.14). However, the mean genetic distance between each sequence within the samples collected from the Yekaterinburg IDU-A variant subset and the IDU-A consensus is 2.51 +/- 1.06 (range 1.36-4.66) and considerably higher than in South Russia in 1996 (0.79 +/- 0.51, range 0.38-1.90). The current HIV-1 epidemic in Russia is almost entirely caused by a highly homogeneous A-subtype strain, which will influence vaccine development strategies and must be taken into account in the quality control of molecular tests for the diagnosis of HIV-1.