The Effect of Genital Tract Infections on HIV-1 Shedding in the Genital Tract: A Systematic Review and Meta-Analysis

This article reviews the effect of genital tract infections and associated clinical conditions on the detection and concentration of HIV-1 shedding in the genital tract. A search of the PubMed, Embase, and AIDSearch databases was conducted. Meta-analysis was performed on those studies that reported the effect of genital tract infections on the detection of HIV-1 shedding. Thirty-nine studies met the inclusion criteria. The odds of HIV-1 detection in the genital tract were increased most substantially by urethritis (OR 3.1, 95% CI: 1.1-8.6) and cervicitis (OR 2.7, 95% CI: 1.4-5.2). The odds of HIV-1 detection were also increased significantly in the presence of cervical discharge or mucopus (OR 1.8, 95% CI: 1.2-2.7), gonorrhoea (OR 1.8, 95% CI: 1.2-2.7), chlamydial infection (OR 1.8, 95% CI: 1.1-3.1), and vulvovaginal candidiasis (OR 1.8, 95% CI: 1.3-2.4). Other infections and clinical conditions were found to have no significant effect on the detection of HIV-1, although HSV-2 shedding was found to increase the concentration of HIV-1 shedding, and genital ulcer disease was found to increase the odds of HIV-1 detection significantly after excluding one biased study (OR 2.4, 95% CI: 1.2-4.9). This analysis shows that infections that are associated with significant increases in leukocyte concentrations in the genital tract are also associated with significant increases in HIV-1 shedding. These infections are likely to be particularly important in promoting the sexual transmission and mother-to-child intrapartum transmission of HIV-1, and should therefore be the focus of HIV prevention strategies.