High HIV incidence in a community with high HIV prevalence in rural South Africa: findings from a prospective population-based study

OBJECTIVES: To measure HIV incidence in a rural area of South Africa with high HIV prevalence and to analyze risk factors for acquisition of HIV using a prospective population-based cohort study. METHODS: Data from two rounds (2003-2005) of a large prospective population-based HIV survey in rural KwaZulu-Natal were used to calculate HIV incidence by sex and 5-year age group. Multiple imputations (MI) were used to adjust for selection effects and risk factors for acquiring HIV were examined in Weibull multiple regression. RESULTS: During 5253 person-years at risk, 170 individuals became seropositive. The crude HIV incidence rate per 100 person-years was 3.8 [95% confidence interval (CI), 3.2-4.6] in women aged 15-49 years and 2.3 (95% CI, 1.8-3.1) in men aged 15-54 years. MI significantly increased the HIV incidence rates both in women and men [7.9/100 person-years (95% CI, 7.4-8.4) and 5.1/100 person-years (95% CI 4.1-6.2), respectively]. When holding other factors constant in Weibull multiple regression, the hazard of HIV seroconversion was approximately twice as high in people who were currently unmarried but had a partner than among people who were currently married (P < 0.001) and increased with increasing distance from a government health clinic (P = 0.051) and decreasing distance from a primary road (P = 0.002). CONCLUSION: In this high HIV prevalence community in rural South Africa HIV incidence is very high. The present focus on antiretroviral treatment needs to be balanced with a renewed emphasis on HIV prevention for both sexes.