Risk factors for incidence of sexually transmitted infections among women in South Africa, Tanzania, and Zambia: results from HPTN 055 study.

OBJECTIVE: To determine risk factors for sexually transmitted infections (STIs) among women in Durban and Hlabisa (South Africa), Moshi (Tanzania), and Lusaka (Zambia). STUDY DESIGN: Between 2003 and 2004, 958 women at risk of STIs were enrolled in a 1-year prospective study. They were interviewed at each monthly visit, and samples for STI testing were collected during quarterly and other visits when clinically indicated. RESULTS: The incidence of infections as measured in person-years at risk (PYAR) was as follows: overall trichomoniasis, 31.9/100 PYAR; chlamydial infection in South Africa, 19.5/100 PYAR; chlamydial infection in Tanzania and Zambia, 4.9/100 PYAR; gonorrhea in South Africa, 16.5/100 PYAR; gonorrhea in Tanzania and Zambia, 5.3/100 PYAR; overall syphilis, 7.5/100 PYAR; and overall HIV, 3.8/100 PYAR. The incidence of most STIs was highest among the South African sites, where chlamydial infection and gonorrhea were detected by using a more sensitive assay. Independent risk factors included age, hormonal contraceptive methods, and measures of sexual behavior, including number of sex partners and occurrence of anal sex in the past 3 months. Women with incident HIV infection were at increased risk of chlamydial infection [odds ratio (OR) = 5.5, 95% confidence interval (CI): 2.0-15.2]and gonorrhea (OR = 5.7, 95% CI: 1.9-17.0) in South African sites. Despite ongoing counseling during the study, high-risk sexual behaviors were common, and consistent condom use remained low. CONCLUSIONS: The incidence of STIs, including HIV, was high among women in this study. These findings highlight the urgent need for effective HIV/STI prevention programs in this population.

The value of site preparedness studies for future implementation of phase 2/IIb/III HIV prevention trials: experience from the HPTN 055 study.

OBJECTIVES: To evaluate the preparedness for phase 2/IIb/III microbicide trials at 4 clinical trial sites: Durban and Hlabisa (South Africa), Lusaka (Zambia), and Moshi (Tanzania). DESIGN: A prospective cohort study was undertaken to assess site suitability for microbicide efficacy studies. Study objectives included assessing sites' ability to recruit and retain high-risk women with the appropriate HIV incidence rates needed to conduct microbicide efficacy studies. METHODS: Nine hundred fifty-eight consenting women were enrolled and followed for up to 1 year. Demographic, behavioral, laboratory, and clinical data were collected to determine the incidence rates of HIV, sexually transmitted infections, and pregnancy. RESULTS: Accrual was completed in 6.3, 6.7, 7.1, and 8.3 months in Durban, Hlabisa, Moshi, and Lusaka, respectively. The highest month 12 participant retention rate was recorded in Durban (97%), followed by Hlabisa (94%), Moshi (86%), and Lusaka (93%). Mean overall age of enrolled participants was 28.6 years (ranging from 27.0 to 32.2 years) across sites. Despite condom counseling, rates of condom use were slightly lower at study end. Pregnancy incidence in the study as a whole was 20.2 per 100 women-years (wy). Overall HIV prevalence was 32.5%, and overall HIV incidence was 3.8 per 100 wy (95% confidence interval [CI]: 2.6 to 5.2). HIV incidence per site was 5.3 per 100 wy in Durban (95% CI: 2.7 to 9.2), 6.2 per 100 wy in Hlabisa (95% CI: 3.4 to 10.5); 2.6 per 100 wy in Lusaka (95% CI: 1.0 to 5.8), and 1.4 per 100 wy in Moshi (95% CI: 0.3 to 4.0). CONCLUSIONS: Preparatory studies provide accurate local estimates of HIV incidence, recruitment and retention rates, and behavioral characteristics of targeted populations for large-scale clinical trials. Determining these factors allows for better preparation for design, sample size, and appropriate population for future selection of trial sites. Because of the lower than expected HIV incidence observed at the Moshi site, only the South African and Zambian sites were selected for the phase 2/IIb trial.