Bacterial Vaginosis (BV), a common condition affecting approximately one in three women globally, has long been a source of discomfort and serious health risks, including infertility, premature births, and newborn deaths. While traditionally viewed as an imbalance in vaginal bacteria, a landmark study has unveiled a paradigm shift in our understanding of BV. Researchers have definitively classified BV as a sexually transmitted infection (STI), paving the way for revolutionary changes in its treatment and prevention.
Spearheaded by experts at Monash University and Alfred Health at the Melbourne Sexual Health Centre, this groundbreaking research, published in the esteemed New England Journal of Medicine, challenges conventional approaches to BV. The study’s findings highlight the critical role of sexual transmission in BV recurrence and advocate for a significant change in treatment protocols to include male partners.
For years, the standard medical practice has approached BV as a disruption of the vaginal microbiome. This perspective led to treatments focused solely on women, typically involving a week-long course of oral antibiotics to restore bacterial balance. However, this approach has been plagued by high recurrence rates, with over half of treated women experiencing BV again within just three months. This frustrating cycle underscores the limitations of the current treatment paradigm and highlights the urgent need for more effective solutions.
The researchers conducted a robust clinical trial involving 164 couples in monogamous relationships to investigate the role of sexual transmission in BV. In a departure from standard practice, the study treated BV as a sexually transmitted infection. The results were compelling: treating both sexual partners simultaneously led to significantly higher cure rates and a dramatic reduction in BV recurrence compared to treating women alone. The trial was even halted prematurely due to the overwhelmingly positive outcomes in the partner treatment group, where BV recurrence was halved.
Professor Catriona Bradshaw, a leading author of the study, emphasized the transformative potential of these findings. “This successful intervention is relatively cheap and short and has the potential for the first time to not only improve BV cure for women, but opens up exciting new opportunities for BV prevention, and prevention of the serious complications associated with BV,” she stated. This new understanding of BV as an STI opens doors to more effective treatment strategies and, crucially, preventative measures that could significantly improve women’s health outcomes worldwide.
The multi-center randomized trial meticulously compared two treatment approaches. All women in the study received the standard first-line antibiotic treatment for BV. However, the male partners were randomly assigned to one of two groups. One group received partner-treatment, consisting of both an oral antibiotic and a topical antibiotic cream applied for one week. The other group served as a control, receiving no treatment – mirroring the current global recommendation of treating women only. Couples were monitored for 12 weeks post-treatment to assess the long-term effectiveness of each intervention in preventing BV recurrence.
Dr. Lenka Vodstrcil, another key researcher, highlighted the existing evidence suggesting BV’s STI nature. “We’ve suspected for a long time that it’s a sexually transmitted infection (STI), because it has a similar incubation period (after sex) to most STIs and is associated with the same risk factors as STIs like Chlamydia, such as change in sexual partner and not using condoms.” This research provides crucial evidence to solidify the classification of BV as a New Sti, demanding a shift in how healthcare professionals and individuals approach this prevalent condition.
While previous research had detected BV-associated bacteria on the penis and within the male reproductive system, trials involving male partner treatment had not shown significant improvements in female partners’ cure rates. Professor Bradshaw explained the limitations of these earlier studies: “However, these studies had design limitations, and none used a combination of oral and topical antibiotics to adequately clear BV bacteria in men, especially from the penile-skin site.” The current study’s success lies in its comprehensive approach to treating male partners, effectively targeting BV-related bacteria and breaking the cycle of reinfection.
The findings unequivocally demonstrate that reinfection from untreated partners is a major driver of recurrent BV in women, providing compelling evidence that BV is indeed a sexually transmitted infection. Professor Bradshaw further noted the ongoing scientific efforts to pinpoint the precise bacteria responsible for BV, stating, “Part of the difficulty in establishing whether BV is sexually transmitted has been that we still don’t know precisely which bacteria are the cause, but advances in genomic sequencing are helping us close in on that mystery.”
The immediate impact of this research is already being felt. The Melbourne Sexual Health Centre has swiftly updated its clinical practice to incorporate partner treatment for BV. To facilitate widespread adoption of these new findings, a comprehensive website has been launched, offering essential information for both healthcare professionals and the public on prescribing and accessing partner treatment. Professor Bradshaw emphasized the collaborative effort behind this resource: “This information has been co-designed with consumers and participants in the trial and health professionals to make it accessible to all.”
While changes to national and international treatment guidelines take time, the researchers are committed to ensuring immediate access to accurate information. This proactive approach underscores the urgency and significance of recognizing BV as a new STI and implementing effective partner-based treatment strategies to improve women’s health and well-being globally.
References:
- Male Partner-Treatment to Prevent Recurrence of Bacterial Vaginosis, New England Journal of Medicine (2025). DOI: 10.1056/NEJMoa2405404, https://dx.doi.org/10.1056/NEJMoa2405404
- Christina A. Muzny et al, Bacterial Vaginosis — Time to Treat Male Partners, New England Journal of Medicine (2025). DOI: 10.1056/NEJMe2500373, https://www.nejm.org/doi/10.1056/NEJMe2500373
- New England Journal of Medicine: https://medicalxpress.com/journals/new-england-journal-of-medicine/
- Monash University: https://medicalxpress.com/partners/monash-university/
