1. Washington D.C., USA, 22-27 July 2012www.aids2012.org Antiretroviral therapy for prevention of HIV transmission in HIV-discordant couples: a systematic review of the observational literature HPTN 052 provided clear evidence that early antiretroviral therapy (ART) in HIV-infected partners in serodiscordant couples decreases the risk of sexual transmission (HR=0.04). Prior to HPTN 052, ecological studies and models suggested that sexual transmission is lower in discordant couples in which the infected partner is on ART. To estimate ART effectiveness from the observational literature, we conducted a systematic review.

2. Washington D.C., USA, 22-27 July 2012www.aids2012.org We identified 1814 references and examined 24 in detail. We included 7 observational studies. – 436 episodes of HIV transmission, 71 among treated couples and 365 among untreated couples. The summary rate ratio was 0.34 [95% CI 0.13, 0.92], with substantial heterogeneity (I 2 =73%). – Sensitivity analysis: exclude 2 studies with inadequate person-time data, summary rate ratio = 0.16 [95% CI 0.07, 0.35]. Antiretroviral therapy for prevention of HIV transmission in HIV-discordant couples

3. Washington D.C., USA, 22-27 July 2012www.aids2012.org We also performed subgroup analyses to see if the effect of ART on prevention of HIV transmission differed by the index partner's CD4 cell count. Among couples in which the infected partner had ≥350 CD4 cells/µL, we estimated a rate ratio of 0.02 [95% CI 0.00, 2.87]. In this subgroup, all 61 transmissions were in untreated. Antiretroviral therapy for prevention of HIV transmission in HIV-discordant couples