Association between sexual behavior practices and HIV serostatus of women screened for the Phase 3 CarraguardŽ microbicide trial

Objectives: To evaluate the effect of selected sexual practices on HIV serostatus in participants screened for the Phase 3 CarraguardŽ microbicide trial. Study Design: The Phase 3 CarraguardŽ trial is a randomized clinical trial to test the efficacy of a vaginal microbicide in HIV prevention. 9,657 women were screened across three sites in South Africa: Empilisweni Centre for Wellness, Setshaba Research Center, and Isipingo Clinic. Methods: Sexual behavior data was collected through interviewer-administered questionnaires. HIV testing was conducted at screening. Results: All women reported being sexual active. 99% of the cohort reported a steady sexual partner and10% had sexual partners in addition to their main partner. At two study sites, Setshaba and Isipingo, women who reported multiple sexual partners were significantly more likely to be HIV positive at screening (odds ratio (OR)=1.32, 1.36, respectively). 20% of women reported that their steady partner had other sexual partners. These women were significantly more likely to be HIV positive at screening at two study sites, Setshaba and Isipingo (OR=1.36, 1.68, respectively). 49% of women didn't know if their partner had other sexual partners. Condom use at last vaginal sex varied based on the monogamy of a women's steady partner. 37% of women who reported partners with additional partners used a condom, whereas 31% who reported monogamous partners used a condom. Conclusion: The importance of woman-initiated HIV prevention strategies is reiterated by low reported condom use, lack of mutual monogamy and its strong association with positive HIV serostatus.