Association between bacterial vaginosis and Herpes simplex virus type-2 infection: implications for HIV acquisition studies.

OBJECTIVES

Bacterial vaginosis (BV) and Herpes simplex virus type-2 (HSV-2) have been linked to an increased risk of HIV-1 acquisition. Recent research suggests an association between BV and HSV-2 acquisition, but the converse has not been studied. Here, we investigate whether an association exists between BV and HSV-2 infection

METHODS

We examined the determinants of BV occurrence in a cohort of female sex workers in Burkina Faso. Participants were followed every 3 months for diagnosis of genital infections and report of sexual behaviours. Factors associated with BV occurrence were assessed using generalised estimating equation models.

RESULTS

We enrolled 273 women (mean age, 28 years) and conducted 812 follow-up visits (mean 2.93 visit per woman). Baseline seroprevalence of HIV-1, HSV-2 and recent syphilis were 31.5%, 70.1% and 0.4%, respectively, while baseline prevalence of BV, Trichomonas vaginalis (TV) and Candida albicans were 20.5%, 3.3% and 2.5%, respectively. In multivariable analysis, HSV-2 (relative risk (RR) = 1.73, 95% CI 1.12 to 2.65), HIV-1 (RR = 1.76, 95% CI 1.30 to 2.40), TV (RR = 1.5, 95% CI 1.0 to 2.3), and having > or = 3 sexual partners in the preceding week (RR = 2.2, 95% CI 1.1 to 4.6) were independently associated with BV, while hormonal contraception showed a protective effect (RR = 0.11, 95% CI 0.02 to 0.70).

CONCLUSIONS

HSV-2 infection was associated with BV occurrence in this population. As HSV-2 is strongly linked to HIV-1 acquisition, studies assessing the cofactor effect of BV on HIV acquisition should control for the presence of HSV-2. Further studies are required to investigate the relative effect of asymptomatic HSV-2 shedding and/or genital ulcerations on BV occurrence.