Male-Partner Treatment to Prevent Recurrence of Bacterial Vaginosis

Bacterial vaginosis (BV) is a highly recurrent condition, with over 50% of women experiencing a return of symptoms within three months of standard antimicrobial treatment. Given that BV has characteristics of a sexually transmitted infection, researchers investigated whether treating male partners—who may harbor BV-associated bacteria on the penis—could prevent recurrence in their female partners.

The StepUp trial was an open-label, randomized, controlled trial conducted in Australia. Researchers enrolled 164 monogamous couples where the woman had symptomatic BV. In the intervention group, women received standard first-line antimicrobial therapy, and their male partners received a 7-day course of oral metronidazole (400 mg twice daily) and topical 2% clindamycin cream (applied to the glans and shaft twice daily). The control group received standard care for the woman only. The primary outcome was the recurrence of BV within 12 weeks, defined by Amsel criteria and Nugent scores.

The trial was stopped early by the data and safety monitoring board after 150 couples completed follow-up because the control group showed significantly higher recurrence rates. In the modified intention-to-treat analysis, 35% of women in the partner-treatment group experienced recurrence, compared to 63% in the control group. The absolute risk difference was -2.6 recurrences per person-year. The treatment was generally well-tolerated, with only minor adverse events reported by men, such as nausea, headache, and metallic taste.

This study provides strong evidence that BV recurrence is linked to sexual transmission and that targeting the male partner's microbial carriage can improve clinical outcomes for women. By addressing the potential reservoir of BV-associated bacteria on the male genitalia, clinicians may offer a more effective strategy for managing this chronic, difficult-to-treat condition.