Scientists say that asking their male sexual partners to use antibiotic pills and cream could help women fight recurring bacterial vaginosis, after a trial found this nearly halved the risk of symptoms of this hard-to-treat condition returning.
“Treating male partners made the most significant inroad into improving recurrence rates in women that we have seen for decades,” said Catriona Bradshaw at Monash University in Melbourne, Australia, who led the work.
Bacterial vaginosis (BV) affects around a quarter of women of reproductive age worldwide. It occurs when “harmful” bacteria overgrow in the vagina, causing vaginal discharge to turn greyish-white and smell fishy, with potentially serious complications.
“It increases a woman’s risk of acquiring a broad range of sexually transmitted infections, like HIV, and complications in pregnancy, like premature birth and miscarriage,” she said
Doctors usually treat the condition using antibiotics in the form of pills or a cream that can be applied inside the vagina, but symptoms often recur because having sex seems to reintroduce problematic bacteria, Bradshaw added.
“One in two women will get their BV back within three to six months of the recommended treatment regimen,” noted Bradshaw.
New Scientist reports that to address this, she and her colleagues recruited 137 monogamous women in Australia with bacterial vaginosis, along with their male partners.
All of the women took standard antibiotics for a week, while around half of their partners were given oral antibiotics and told to apply an antibiotic cream to the penis over the same period. The remaining men received no treatment.
Three months later, 63% of the women whose partners weren’t treated had recurring symptoms, while just 35% of the women with partners who received antibiotics experienced a recurrence.
The findings were reported in the New England Journal of Medicine.
“It’s definitely a sizable effect that makes it a worthwhile intervention for this group of women,” said Janneke van de Wijgert at Utrecht University in The Netherlands.
The team didn’t track all of the participants over the long term, but some got back in touch years later to say they remained free of symptoms.
“In the past week, I’ve talked to someone who’s been clear of BV for two years since they participated – and these women were highly recurrent before the trial,” said Lenka Vodstrcil at Monash University.
However, the approach won’t work for women with casual sexual partners, where it may be difficult to get them to adhere to taking antibiotics, said Van de Wijgert. Even in monogamous relationships, men may not always be willing to take antibiotics, she added.
“We’ve seen this with condom use, which also reduces BV recurrence – it can be really difficult for women to get their male partners to use condoms.”
Study details
Male-Partner Treatment to Prevent Recurrence of Bacterial Vaginosis
Lenka Vodstrcil, Erica Plummer, Christopher Fairley, Jane Hocking, Matthew Law, Kathy Petoumenos, Deborah Bateson, et al for the StepUp Team
Published in the New England Journal of Medicine on 5 March 2025
Abstract
Background
Bacterial vaginosis affects one third of reproductive-aged women, and recurrence is common. Evidence of sexual exchange of bacterial vaginosis–associated organisms between partners suggests that male-partner treatment may increase the likelihood of cure.
Methods
This open-label, randomised, controlled trial involved couples in which a woman had bacterial vaginosis and was in a monogamous relationship with a male partner. In the partner-treatment group, the woman received first-line recommended antimicrobial agents and the male partner received oral and topical antimicrobial treatment (metronidazole 400-mg tablets and 2% clindamycin cream applied to penile skin, both twice daily for 7 days). In the control group, the woman received first-line treatment and the male partner received no treatment (standard care). The primary outcome was recurrence of bacterial vaginosis within 12 weeks.
Results
A total of 81 couples were assigned to the partner-treatment group, and 83 couples were assigned to the control group. The trial was stopped by the data and safety monitoring board after 150 couples had completed the 12-week follow-up period because treatment of the woman only was inferior to treatment of both the woman and her male partner. In the modified intention-to-treat population, recurrence occurred in 24 of 69 women (35%) in the partner-treatment group (recurrence rate, 1.6 per person-year; 95% confidence interval [CI], 1.1 to 2.4) and in 43 of 68 women (63%) in the control group (recurrence rate, 4.2 per person-year; 95% CI, 3.2 to 5.7), which corresponded to an absolute risk difference of −2.6 recurrences per person-year (95% CI, −4.0 to −1.2; P<0.001). Adverse events in treated men included nausea, headache, and metallic taste.
Conclusions
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 bacterial vaginosis within 12 weeks than standard care.
NEJM article – Male-Partner Treatment to Prevent Recurrence of Bacterial Vaginosis (Open access)
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