title: Emerging HIV infections with distinct subtypes of HIV-1 infection among injection drug users from geographically separate locations in Guangxi Province, China.
abstract: Heroin users from Guangxi province, a southern province of China that borders Vietnam in the south and Yunnan province in China in the west, were studied for prevalence and risk factors for HIV-1 infection. Viral env sequences from HIV-1-positive individuals were also determined for subtypes of HIV-1. The overall HIV prevalence among 227 heroin users was 40%. Most had used drugs for < or = 3 years. Sharing of injection equipment and unprotected sex were significantly associated with HIV-1 infection. Subtypes C and E HIV-1 were detected in infected heroin users and were sharply segregated in two geographic locations: only subtype C was found in a border city with Yunnan province, whereas only subtype E was found in a city bordering northern Vietnam. HIV-1 strains within each subtype were remarkably homogenous, with a mean intersubject DNA distance of 2.32% for subtype E and 1.13% for subtype C, respectively. Phylogenetic analysis of C2-V5 region of Guangxi subtype E env sequences revealed significant clustering with subtype E sequences from southern Vietnam and Cambodia. These results suggest that HIV-1 infection among heroin users in Guangxi represents two emerging epidemics initiated from distinct sources: one from Vietnam and another from Yunnan province. Factors associated with HIV-1 infection were not restricted to injection practices. Unprotected sexual behaviors are likely to increase the probability of HIV transmission beyond this high-risk population. Designing and implementing effective intervention strategies targeted toward both injection drug use and high risk sexual behavior are urgently needed to further reduce HIV-1 spread in China.
authors.affiliation: Department of Molecular Microbiology and Immunology, Johns Hopkins University School of Hygiene and Public Health, Baltimore, Maryland 21205, USA. xfyu@jhsph.edu
authors.forename: X F
authors.initials: XF
authors.lastname: Yu
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: Y
authors.initials: Y
authors.lastname: Shao
authors.forename: C
authors.initials: C
authors.lastname: Beyrer
authors.forename: B
authors.initials: B
authors.lastname: Liu
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: W
authors.initials: W
authors.lastname: Liu
authors.forename: J
authors.initials: J
authors.lastname: Yang
authors.forename: S
authors.initials: S
authors.lastname: Liang
authors.forename: R P
authors.initials: RP
authors.lastname: Viscidi
authors.forename: J
authors.initials: J
authors.lastname: Gu
authors.forename: G
authors.initials: G
authors.lastname: Gurri-Glass
authors.forename: S
authors.initials: S
authors.lastname: Lai
mesh_terms: D002681:China / Q000453:epidemiology; D004279:DNA, Viral / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015686:Gene Products, env / Q000737:chemistry; D015658:HIV Infections / Q000150:complications / Q000453:epidemiology / Q000821:virology*; D015497:HIV-1 / Q000145:classification*; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012307:Risk Factors; D015819:Substance Abuse, Intravenous / Q000150:complications*
chemical_list: D004279:DNA, Viral; D015686:Gene Products, env