The role of herpes simplex virus type 2 and other genital infections in the acquisition of HIV-1 among high-risk women in northern Tanzania

Background. We examined the role of herpes simplex virus type 2 ( HSV-2) and other genital infections on human immunodeficiency virus type 1 ( HIV-1) incidence in a cohort study conducted between 2002 and 2005 among female bar/hotel workers in Moshi, Tanzania. Methods. At baseline and every 3 months thereafter, participants were interviewed, and blood and genital samples were collected. Predictors of HIV-1 incidence were evaluated using a Cox proportional hazards regression model. Results. Of 845 women who were HIV-1 seronegative at baseline, 689 ( 81.5%) were monitored in the study for a total of 698.6 person-years at risk ( PYARs). The overall HIV-1 incidence was 4.6/100 PYARs ( 95% confidence interval [ CI], 3.0-6.2/100 PYARs), and condom use was very low. After adjustment for other risk factors, the risk of HIV-1 was increased among women with HSV-2 at baseline ( hazard ratio [ HR], 4.3 [ 95% CI, 1.5-12.4]) and in those who acquired HSV-2 during the study period ( HR, 5.5 [ 95% CI, 1.2-25.4]). Other independent predictors of HIV-1 were baseline chlamydial infection ( HR, 5.2), bacterial vaginosis ( HR, 2.1), and the occurrence of genital ulcers ( HR, 2.7). Conclusion. HSV-2 and other genital infections were the most important risk factors for HIV-1. Control of these infections could help to reduce HIV-1 incidence in this population.