Incident herpes simplex virus type 2 infection increases the risk of subsequent episodes of bacterial vaginosis.

Herpes simplex virus type 2 (HSV-2) infected women have a higher prevalence of bacterial vaginosis (BV) compared to HSV-2-seronegative women. To explore the temporal association between these conditions, we evaluated the frequency of BV episodes before and after HSV-2 acquisition in a prospective study of 406 HSV-2/HIV-1-seronegative Kenyan women, of whom 164 acquired HSV-2. Incident HSV-2 was associated with increased likelihood of BV (adjusted OR, 1.28; 95% CI, 1.05-1.56; P = .01). Our findings strengthen the evidence for a causal link between genital HSV-2 infection and disruption of the vaginal microbiota.