title: [Distribution of recombinant human immunodeficiency virus type-1 CRF01_AE strains in China and its sequence variations in the env V3-C3 region].
abstract: OBJECTIVE
  To characterize CRF01_AE strains of recombinant human immunodeficiency virus type-1 (HIV-1) found in the Second National Molecular Epidemiology Study on HIV in China and to analyze its sequence variation in the env V3-C3 region during the First National Molecular Epidemiology Study (NMES1, 1996 - 1998) to the Second National Molecular Epidemiology Study (NMES2, 2001 - 2002).
  
  
  METHODS
  DNA was extracted from peripheal blood mononuclear cells of the subjects with HIV infection. The env C2-V4 region of HIV-1 was amplified with nested polymerase chain reaction (n-PCR). PCR products were directly sequenced using ABI 377 DNA sequencer, then the gene-based phylogenetic tree was constructed and its variation of amino acids was analyzed with GCG software.
  
  
  RESULTS
  Totally, 169 strains of recombinant HIV-1 CRF01_AE were identified from blood samples collected from different high risk groups in 17 of 31 provinces, municipalities and autonomous regions all over China by the end of 2002. Although sexual transmission still dominated during NMES1 (62.2%, 23/37) and NMES2 (55.3%, 73/132), prevalence of HIV-1 CRF01_AE in intravenous drug users (IDUs) increased to 41.6% (57/137) during NMES2 from 27% (10/37) during NMES1. Phylogenetic tree analysis showed that HIV-1 CRF01_AE strains prevalent in IDUs during NMES2 did not cluster with those prevalent in the subjects infected by sexual transmission during NMES2 and those in IDUs during NMES1. The amino acid residues of V3 region of HIV-1 CRF01_AE in IDUs were relatively conservative, but the sixth, eighth, ninth, tenth, twelfth, fifteenth, sixteenth amino acid residues of C3 region displayed regular changes.
  
  
  CONCLUSIONS
  HIV-1 CRF01_AE strain has been introduced into inland provinces from southeastern coast areas and southwestern border areas, with an increasing prevalence in IDUs. The sequence of env V3-C3 region of recombinant HIV-1 CRF01_AE strains prevalent in IDUs during NMES2 was obviously different from that during NMES1, suggesting that HIV-1 CRF01_AE strains prevalent in IDUs during NMES2 might come from a new source and have a potential to spread.
authors.affiliation: National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Xing
authors.forename: Hao
authors.initials: H
authors.lastname: Liang
authors.forename: Zhuo-Yue
authors.initials: ZY
authors.lastname: Wan
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.forename: Min
authors.initials: M
authors.lastname: Wei
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Ma
authors.forename: Qi
authors.initials: Q
authors.lastname: Guan
authors.forename: Yu
authors.initials: Y
authors.lastname: Quan
authors.forename: Kun-Xue
authors.initials: KX
authors.lastname: Hong
authors.forename: Yi-Ming
authors.initials: YM
authors.lastname: Shao
mesh_terms: D000595:Amino Acid Sequence; D002681:China / Q000453:epidemiology; D015752:Genes, env / Q000235:genetics*; D014644:Genetic Variation; D016679:Genome, Viral; D015658:HIV Infections / Q000453:epidemiology* / Q000235:genetics* / Q000821:virology; D015497:HIV-1 / Q000145:classification / Q000235:genetics*; D006801:Humans; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D011995:Recombination, Genetic; D017386:Sequence Homology, Amino Acid; D015819:Substance Abuse, Intravenous / Q000821:virology*
chemical_list: D012367:RNA, Viral