Characteristics of HIV-1 discordant couples enrolled in a trial of HSV-2 suppression to reduce HIV-1 transmission: the partners study

Lingappa,J.R.; Kahle,E.; Mugo,N.; Mujugira,A.; Magaret,A.; Baeten,J.; Bukusi,E.A.; Cohen,C.R.; Katabira,E.; Ronald,A.; Kiarie,J.; Farquhar,C.; Stewart,G.J.; Makhema,J.; Essex,M.; Were,E.; Fife,K.; Debruyn,G.; Gray,G.; McIntyre,J.; Manongi,R.; Kapiga,S.; Coetzee,D.; Allen,S.; Inambao,M.; Kayitenkore,K.; Karita,E.; Kanweka,W.; Delany,S.; Rees,H.; Vwalika,B.; Coombs,R.W.; Morrow,R.; Whittington,W.; Corey,L.; Wald,A.; Celum,C. PLoS One. 2009;4(4):e5272
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BACKGROUND: The Partners HSV-2/HIV-1 Transmission Study (Partners Study) is a phase III, placebo-controlled trial of daily acyclovir for genital herpes (HSV-2) suppression among HIV-1/HSV-2 co-infected persons to reduce HIV-1 transmission to their HIV-1 susceptible partners, which requires recruitment of HIV-1 serodiscordant heterosexual couples. We describe the baseline characteristics of this cohort. METHODS: HIV-1 serodiscordant heterosexual couples, in which the HIV-1 infected partner was HSV-2 seropositive, had a CD4 count >or=250 cells/mcL and was not on antiretroviral therapy, were enrolled at 14 sites in East and Southern Africa. Demographic, behavioral, clinical and laboratory characteristics were assessed. RESULTS: Of the 3408 HIV-1 serodiscordant couples enrolled, 67% of the HIV-1 infected partners were women. Couples had cohabitated for a median of 5 years (range 2-9) with 28% reporting unprotected sex in the month prior to enrollment. Among HIV-1 susceptible participants, 86% of women and 59% of men were HSV-2 seropositive. Other laboratory-diagnosed sexually transmitted infections were uncommon (<5%), except for Trichomonas vaginalis in 14% of HIV-1 infected women. Median baseline CD4 count for HIV-1 infected participants was 462cells/mcL and median HIV-1 plasma RNA was 4.2 log(10) copies/mL. After adjusting for age and African region, correlates of HIV-1 RNA level included male gender (+0.24 log(10) copies/mL; p<0.001) and CD4 count (-0.25 and -0.55 log(10) copies/mL for CD4 350-499 and >500 relative to <350, respectively, p<0.001). CONCLUSIONS: The Partners Study successfully enrolled a cohort of 3408 heterosexual HIV-1 serodiscordant couples in Africa at high risk for HIV-1 transmission. Follow-up of this cohort will evaluate the efficacy of acyclovir for HSV-2 suppression in preventing HIV-1 transmission and provide insights into biological and behavioral factors determining heterosexual HIV-1 transmission.