title: Molecular linkage tracing of HIV-1 transmission events in seroconcordant couples in Guangxi Province, Southeastern China.
abstract: BACKGROUND
  Guangxi Province in Southeastern China has one of the highest HIV-1 infection and transmission rates in stable couples. However, the mode of transmission at the molecular level has seldom been reported amongst this group. It is important to investigate this issue to support the treatment-as-prevention approach and for efficient interventions.
  
  
  METHODS
  HIV-1 subgenomic regions (1.2 kb ofpoland a 660-bpenvC2V5 fragment) were sequenced in 42 couples. A couple linkage assessment was performed by phylogenetic analysis of sequences and Bayesian analysis of genetic distances. A subset of pairs was selected for single-genome amplification.
  
  
  RESULTS
  Thirty-five pairs (83.3 %, 35/42) were identified as linked, 3 pairs (7.1 %, 3/42) were identified as indeterminate, and 4 pairs (9.5 %) were identified as unlinked. The predominant intra-couple-transmitted HIV-1 subtype was CRF01_AE (80 %, 28/35). The median genetic distance of linked couples was 0.5 %.
  
  
  CONCLUSIONS
  The majority of HIV-1 transmission events in this study occurred within the partnership, and the predominant HIV-1 subtype was CRF01_AE. Further research on the mode of HIV transmission in other locations is needed.
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.|Department of Infectious Diseases, Peking Union Medical College Hospital, Beijing, People's Republic of China.
authors.forename: Nidan
authors.initials: N
authors.lastname: Wang
authors.affiliation: Guangxi Center for Disease Prevention and Control, Nanning, People's Republic of China.
authors.forename: Zhenzhu
authors.initials: Z
authors.lastname: Tang
authors.affiliation: Department of Infectious Diseases, Peking Union Medical College Hospital, Beijing, People's Republic of China.
authors.forename: Yijia
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.
authors.forename: Peiyan
authors.initials: P
authors.lastname: Xie
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.|Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China.
authors.forename: Yiming
authors.initials: Y
authors.lastname: Shao
keywords: HIV-1 transmission; Phylogenetic analysis, Bayesian analysis; Seroconcordant couples; Serodiscordant couples