title: Absence of transmission from HIV-infected individuals with HAART to their heterosexual serodiscordant partners.
abstract: BACKGROUND
  Further studies are needed to evaluate the level of effectiveness and durability of HAART to reduce the risk of HIV sexual transmission in serodiscordant couples having unprotected sexual practices.
  
  
  METHODS
  A cross-sectional study was conducted with prospective cohort of heterosexual HIV serodiscordant couples where the only risk factor for HIV transmission to the uninfected partner (sexual partner) was the sexual relationship with the infected partner (index case). HIV prevalence in sexual partners at enrolment and seroconversions in follow-up were compared by antiretroviral treatment in the index partner, HIV plasma viral load in index cases and sexual risk exposures in sexual partners. In each visit, an evaluation of the risks for HIV transmission, preventive counselling and screening for genitourinary infections in the sexual partner was performed, as well as the determination of the immunological and virological situation and antiretroviral treatment in the index case.
  
  
  RESULTS
  At enrolment no HIV infection was detected in 202 couples where the index case was taking HAART. HIV prevalence in sexual partners was 9.6% in 491 couples where the index case was not taking antiretroviral treatment (p<0.001). During follow-up there was no HIV seroconversion among 199 partners whose index case was taking HAART, accruing 7600 risky sexual exposures and 85 natural pregnancies. Among 359 couples whose index case was not under antiretroviral treatment, over 13,000 risky sexual exposures and 5 HIV seroconversions of sexual partners were recorded. The percentage of seroconversion among couples having risky sexual intercourse was 2.5 (95% confidence interval [CI]: 1.1-5.6) when the index case did not undergo antiretroviral treatment and zero (95% CI: 0-3.2) when the index case received HAART.
  
  
  CONCLUSIONS
  The risk of sexual transmission of HIV from individuals with HAART to their heterosexual partners can become extremely low.
authors.affiliation: Centro Sanitario Sandoval, Instituto de Investigación Sanitaria San Carlos (IdISSC), Madrid, Spain. Electronic address: jromero@salud.madrid.org.
authors.forename: Jorge
authors.initials: J
authors.lastname: Del Romero
authors.affiliation: CIBER de Epidemiología y Salud Pública (CIBERESP), Spain; Centro Nacional de Epidemiología, Instituto de Salud Carlos III (ISCIII), Madrid, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Río
authors.affiliation: Instituto de Salud Pública de Navarra, Pamplona, Spain; CIBER de Epidemiología y Salud Pública (CIBERESP), Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Castilla
authors.affiliation: Centro Sanitario Sandoval, Instituto de Investigación Sanitaria San Carlos (IdISSC), Madrid, Spain.
authors.forename: Begoña
authors.initials: B
authors.lastname: Baza
authors.affiliation: Centro Nacional de Epidemiología, Instituto de Salud Carlos III (ISCIII), Madrid, Spain.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Paredes
authors.affiliation: Centro Sanitario Sandoval, Instituto de Investigación Sanitaria San Carlos (IdISSC), Madrid, Spain.
authors.forename: Mar
authors.initials: M
authors.lastname: Vera
authors.affiliation: Centro Sanitario Sandoval, Instituto de Investigación Sanitaria San Carlos (IdISSC), Madrid, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Rodríguez
mesh_terms: D000328:Adult; D023241:Antiretroviral Therapy, Highly Active; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D005831:Genital Diseases, Female / Q000453:epidemiology; D015483:HIV Antibodies / Q000097:blood; D015658:HIV Infections / Q000188:drug therapy / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission*; D006679:HIV Seropositivity; D020010:Heterosexuality; D006801:Humans; D008297:Male; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000517:prevention & control; D011446:Prospective Studies; D012367:RNA, Viral / Q000097:blood; D012307:Risk Factors; D012747:Sexual Partners; D012749:Sexually Transmitted Diseases / Q000453:epidemiology; D047568:Unsafe Sex; D019562:Viral Load; D055815:Young Adult
chemical_list: D015483:HIV Antibodies; D012367:RNA, Viral
keywords: Antiretroviral therapy; HIV; HIV prevention; HIV serodiscordant couples; Parejas heterosexuales serodiscordantes al VIH; Prevención del VIH; Sexual transmission; Terapia antirretroviral; Transmisión sexual; VIH