Treatment Success Following Standard Antibiotic Treatment for Bacterial Vaginosis Is Not Associated With Pretreatment Genital Immune or Microbial Parameters

Background: Bacterial vaginosis (BV) is a proinflammatory genital condition associated with adverse reproductive health outcomes, including increased HIV incidence. However, BV recurrence rates are high after standard antibiotic treatment. While the composition of the vaginal microbiota before BV treatment may be linked to BV recurrence, it is unclear whether the preceding genital immune milieu is predictive of treatment success.

Methods: Here we assessed whether baseline vaginal soluble immune factors or the composition of the vaginal microbiota predicted treatment success 1 month after metronidazole treatment in 2 separate cohorts of women with BV, 1 in the United States and 1 in Kenya; samples within 48 hours of BV treatment were also available for the US cohort.

Results: Neither soluble immune factors nor the composition of the vaginal microbiota before BV treatment was associated with treatment response in either cohort. In the US cohort, although the absolute abundances of key vaginal bacterial taxa pretreatment were not associated with treatment response, participants with sustained BV clearance had a more pronounced reduction in the absolute abundance of Gardnerella vaginalis immediately after treatment.

Conclusions: Pretreatment immune and microbial parameters were not predictive of BV treatment success in these clinical cohorts.