title: HIV-1 transmission among HIV-1 discordant couples before and after the introduction of antiretroviral therapy.
abstract: OBJECTIVE
  To evaluate the impact of antiretroviral therapy (ART) on HIV-1 transmission rates among HIV-1 discordant couples in Rakai, Uganda.
  
  
  METHODS
  Observational cohort study.
  
  
  METHODS
  HIV-1 discordant couples were retrospectively identified between 2004 and 2009. Study participants underwent annual screening for HIV-1 and were interviewed to evaluate risk behaviors. Participants were offered voluntary counseling and testing and provided with risk reduction counseling. Free ART was offered to participants with a CD4 cell count of 250 cells/μl or less or WHO stage IV disease. HIV-1 incidence and sexual risk behaviors were compared before and after the HIV-1-positive index partners started ART.
  
  
  RESULTS
  Two hundred and fifty HIV-1 discordant couples were followed between 2004 and 2009 and 32 HIV-1-positive partners initiated ART. Forty-two HIV-1 transmissions occurred over 459.4 person-years prior to ART initiation, incidence 9.2/100 person-years [95% confidence interval (CI) 6.59-12.36]. In 32 couples in which the HIV-1 index partners started ART, no HIV-1 transmissions occurred during 53.6 person-years. The 95% CI for the incidence rate difference was -11.91 to -6.38 (P = 0.0097). Couples reported more consistent condom use during ART use, but there was no significant difference in the number of sexual partners or other risk behaviors. Viral load was markedly reduced in persons on ART.
  
  
  CONCLUSIONS
  HIV-1 transmission may be reduced among HIV-1 discordant couples after initiation of ART due to reductions in HIV-1 viral load and increased consistent condom use.
authors.affiliation: National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, USA. sjr@jhmi.edu
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Reynolds
authors.forename: Frederick
authors.initials: F
authors.lastname: Makumbi
authors.forename: Gertrude
authors.initials: G
authors.lastname: Nakigozi
authors.forename: Joseph
authors.initials: J
authors.lastname: Kagaayi
authors.forename: Ronald H
authors.initials: RH
authors.lastname: Gray
authors.forename: Maria
authors.initials: M
authors.lastname: Wawer
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Quinn
authors.forename: David
authors.initials: D
authors.lastname: Serwadda
mesh_terms: D000293:Adolescent; D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D018562:Disease Transmission, Infectious; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000453:epidemiology / Q000635:transmission*; D015497:HIV-1; D006801:Humans; D008297:Male; D012309:Risk-Taking; D012747:Sexual Partners / Q000523:psychology; D014454:Uganda / Q000453:epidemiology; D019562:Viral Load; D055815:Young Adult
chemical_list: D044966:Anti-Retroviral Agents