In a randomized controlled trial, researchers have demonstrated that treating male partners of women with bacterial vaginosis could reduce the rate of recurrence within 12 weeks.
In the StepUp trial, published in The New England Journal of Medicine and conducted across three Australian states, the researchers found that when male partners received both oral metronidazole and topical clindamycin cream along with standard treatment for female partners, bacterial vaginosis (BV) recurrence dropped to 35% compared with 63% among women whose male partners received no treatment.
"The addition of combined oral and topical antimicrobial therapy for male partners to treatment of women for bacterial vaginosis resulted in a lower rate of recurrence of [BV] within 12 weeks than standard care," the study authors wrote.
The trial was halted early by the data and safety monitoring board after 150 couples completed the 12-week follow-up because the treatment of just women was found to be significantly inferior to the treatment of both partners.
In the modified intention-to-treat analysis, recurrence occurred in 35% (n = 24/69) of the women in the partner-treatment group (recurrence rate = 1.6 per person-year, 95% confidence interval [CI] = 1.1–2.4) compared with 63% (n = 43/68) of the women in the control group (recurrence rate = 4.2 per person-year, 95% CI = 3.2–5.7). This corresponded to an absolute risk difference of –2.6 recurrences per person-year (95% CI = –4.0 to –1.2, P < .001).
The mean time until recurrence was 73.9 days in the partner-treatment group vs 54.5 days in the control group, representing a difference in restricted mean survival time of 19.3 days (95% CI = 11.5–27.1, P < .001).
BV affects approximately 30% of reproductive-aged women worldwide and is associated with significant obstetric and gynecologic sequelae. Current guidelines recommend metronidazole or clindamycin as first-line treatment in affected women, but recurrence rates within 3 months typically exceed 50%.
The StepUp trial enrolled couples in which women had symptomatic BV (meeting at least three of four Amsel criteria and a Nugent score of 4 to 10) and were in a monogamous relationship with a male partner for at least 8 weeks. In the partner-treatment group, male partners received oral metronidazole (400-mg tablets twice daily) and topical 2% clindamycin cream applied to penile skin twice daily, both for 7 days.
The regimen specifically targeted both urethral and cutaneous penile carriage of BV-associated organisms, which prior studies had indicated might serve as reservoirs for reinfection.
The researchers noted that the trial population had a high burden of risk factors for recurrence.
"Most women (87%) had a history of [BV] and an uncircumcised male partner (80%), and nearly a third used an [intrauterine device]," emphasized senior study author Catriona S. Bradshaw, PhD.
Adverse events reported by treated men included nausea (14%), headache (12%), and metallic taste (7%). Topical adverse events were uncommon, with only four men reporting mild penile irritation.
The researchers indicated that unlike previous trials that used only oral antimicrobial therapy in male partners, this study specifically targeted both urethral and cutaneous penile carriage of BV-associated organisms.
"Our trial findings align with microbiologic evidence from our pilot studies, which showed that oral and topical antimicrobial therapy favorably altered the microbiota composition at both penile sites and was associated with lower-than-expected rates of recurrence in women," the study authors stated.
The study may have significant implications for clinical practice, potentially changing the standard of care for treating BV from the current woman-only approach to include treatment of male partners. This could significantly reduce the substantial health and economic burden of recurrent BV worldwide.
Full disclosures can be found in the study.