title: Molecular tracing of sexual HIV Type 1 transmission in the southwest border of China.
abstract: Since the first outbreak of HIV-1 was reported in heroin users in China in 1989, HIV-1 has spread steadily among injection drug users, leading to an exponential growth of nationwide outbreaks from 1998 to 2004. However, the impact of sexual transmission on outbreaks of HIV in China's general population is still unclear. Through a governmental HIV/AIDS surveillance program, an HIV serological study was conducted in volunteers between 1996 and 2005 in Xishuangbanna Dai Autonomous Prefecture of Yunnan province. We performed the transmission reconstruction by molecular epidemiological tracing in a subset of the HIV-1-seropositive individuals diagnosed during this survey. Neighbor joining and maximum likelihood trees based on the HIV-1 pol and env genes were implemented to provide information on putative epidemiological links, which were then confirmed by contact tracing. Of 25,390 volunteers, 501 (2%) accumulated cases of HIV-1 infection (21.1% in needle-sharing drug users, 77.3% in heterosexual adults, 0.4% in homosexual adults, and 1.2% in children born from infected mothers) were diagnosed. Among 44 heterosexually infected and antiretroviral-naive local-traceable individuals (27 infected with HIV-1 subtype CRF01_AE, 15 with CRF08_BC, 1 with G, and 1 with a new B/C recombinant), 18 (40.9%) were coclustered into 8 transmission chains with an average size of 2.25 infections per chain. Phylogenetic and epidemiological linkages confirmed eight heterosexual transmission events. This is the first report providing molecular epidemiological evidence of heterosexual transmission of HIV-1 in China's general population. The reconstruction of transmission of current HIV-1 outbreaks by molecular epidemiological tracing is instrumental in identifying sources of the epidemic and in defining prevention strategies.
authors.affiliation: Sino-French Collaboration Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Tsinghua University, Beijing, People's Republic of China.
authors.forename: Linlin
authors.initials: L
authors.lastname: Bao
authors.forename: Nicole
authors.initials: N
authors.lastname: Vidal
authors.forename: Hua
authors.initials: H
authors.lastname: Fang
authors.forename: Wei
authors.initials: W
authors.lastname: Deng
authors.forename: Song
authors.initials: S
authors.lastname: Chen
authors.forename: Weizhong
authors.initials: W
authors.lastname: Guo
authors.forename: Chuan
authors.initials: C
authors.lastname: Qin
authors.forename: Martine
authors.initials: M
authors.lastname: Peeters
authors.forename: Eric
authors.initials: E
authors.lastname: Delaporte
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Andrieu
authors.forename: Wei
authors.initials: W
authors.lastname: Lu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002681:China / Q000453:epidemiology; D016358:Contact Tracing; D004196:Disease Outbreaks; D018562:Disease Transmission, Infectious; D005260:Female; D006679:HIV Seropositivity / Q000453:epidemiology* / Q000635:transmission; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D016485:Needle Sharing; D012307:Risk Factors; D018571:Sentinel Surveillance; D012725:Sexual Behavior; D054299:env Gene Products, Human Immunodeficiency Virus / Q000235:genetics; D054302:pol Gene Products, Human Immunodeficiency Virus / Q000235:genetics
chemical_list: D054299:env Gene Products, Human Immunodeficiency Virus; D054302:pol Gene Products, Human Immunodeficiency Virus