title: Effect of Condom Use on Per-act HSV-2 Transmission Risk in HIV-1, HSV-2-discordant Couples.
abstract: BACKGROUND
  The efficacy of condoms for protection against transmission of herpes simplex virus type 2 (HSV-2) has been examined in a variety of populations with different effect measures. Often the efficacy has been assessed as change in hazard of transmission with consistent vs inconsistent use, independent of the number of acts. Condom efficacy has not previously measured on a per-act basis.
  
  
  METHODS
  We examined the per-act HSV-2 transmission rates with and without condom use among 911 African HSV-2 and human immunodeficiency virus type 1 (HIV-1) serodiscordant couples followed for an average of 18 months in an HIV prevention study. Infectivity models were used to associate the log10 probability of HSV-2 transmission over monthly risk periods with reported numbers of protected and unprotected sex acts. Condom efficacy was computed as the proportionate reduction in transmission risk for protected relative to unprotected sex acts.
  
  
  RESULTS
  Transmission of HSV-2 occurred in 68 couples, including 17 with susceptible women and 51 with susceptible men. The highest rate of transmission was from men to women: 28.5 transmissions per 1000 unprotected sex acts. We found that condoms were differentially protective against HSV-2 transmission by sex; condom use reduced per-act risk of transmission from men to women by 96% (P < .001) and marginally from women to men by 65% (P = .060).
  
  
  CONCLUSIONS
  Condoms are recommended as an effective preventive method for heterosexual transmission of HSV-2.
authors.affiliation: Department of Laboratory Medicine Department of Biostatistics Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center.
authors.forename: Amalia S
authors.initials: AS
authors.lastname: Magaret
authors.affiliation: Department of Global Health Department of Epidemiology, University of Washington.
authors.forename: Andrew
authors.initials: A
authors.lastname: Mujugira
authors.affiliation: Department of Biostatistics Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center.
authors.forename: James P
authors.initials: JP
authors.lastname: Hughes
authors.affiliation: Department of Global Health Department of Pediatrics Department of Medicine, University of Washington, Seattle.
authors.forename: Jairam
authors.initials: J
authors.lastname: Lingappa
authors.affiliation: Center for Microbiology Research, Kenya Medical Research Institute (KEMRI), Nairobi.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Bukusi
authors.affiliation: Sanofi Pasteur, Swiftwater, Pennsylvania.
authors.forename: Guy
authors.initials: G
authors.lastname: DeBruyn
authors.affiliation: Wits Reproductive Health and HIV Institute, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Sinead
authors.initials: S
authors.lastname: Delany-Moretlwe
authors.affiliation: Department of Medicine, Indiana University, Indianapolis.
authors.forename: Kenneth H
authors.initials: KH
authors.lastname: Fife
authors.affiliation: Perinatal HIV Research Unit, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Glenda E
authors.initials: GE
authors.lastname: Gray
authors.affiliation: London School of Hygiene and Tropical Medicine, United Kingdom.
authors.forename: Saidi
authors.initials: S
authors.lastname: Kapiga
authors.affiliation: Rwanda-Zambia HIV Research Group, Kigali, Rwanda, Lusaka, Zambia.
authors.forename: Etienne
authors.initials: E
authors.lastname: Karita
authors.affiliation: Center for Microbiology Research, Kenya Medical Research Institute (KEMRI), Nairobi.
authors.forename: Nelly R
authors.initials: NR
authors.lastname: Mugo
authors.affiliation: Wits Reproductive Health and HIV Institute, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Helen
authors.initials: H
authors.lastname: Rees
authors.affiliation: Department of Medicine, University of Manitoba, Winnipeg, Canada Infectious Disease Institute, Makerere University, Kampala, Uganda.
authors.forename: Allan
authors.initials: A
authors.lastname: Ronald
authors.affiliation: Rwanda-Zambia HIV Research Group, Kigali, Rwanda, Lusaka, Zambia Department of Obstetrics and Gynaecology, University of Zambia, School of Medicine, Lusaka.
authors.forename: Bellington
authors.initials: B
authors.lastname: Vwalika
authors.affiliation: Department of Reproductive Health, Moi University, Eldoret, Kenya.
authors.forename: Edwin
authors.initials: E
authors.lastname: Were
authors.affiliation: Department of Global Health Department of Epidemiology, University of Washington, Department of Medicine, University of Washington, Seattle.
authors.forename: Connie
authors.initials: C
authors.lastname: Celum
authors.affiliation: Department of Laboratory Medicine Department of Epidemiology, University of Washington, Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center Department of Medicine, University of Washington, Seattle.
authors.forename: Anna
authors.initials: A
authors.lastname: Wald
mesh_terms: D017280:Condoms; D018562:Disease Transmission, Infectious / Q000517:prevention & control*; D005191:Family Characteristics; D005260:Female; D015658:HIV Infections / Q000150:complications*; D006558:Herpes Genitalis / Q000517:prevention & control* / Q000635:transmission*; D018258:Herpesvirus 2, Human / Q000302:isolation & purification*; D006801:Humans; D017053:Infection Control / Q000379:methods*; D008297:Male; D018570:Risk Assessment
keywords: HIV; HSV-2; condom; efficacy; transmission