New antibiotic combinations aim to prevent recurrent bacterial vaginosis

Researchers and clinicians from Monash University and Bayside Health's Melbourne Sexual Health Centre are trialing new combinations of antibiotics to treat persistent bacterial vaginosis (BV), following their landmark discovery that the condition is sexually transmissible.

Bacterial vaginosis is the most common vaginal condition among women of reproductive age and is caused by a loss of healthy vaginal bacteria and an overgrowth of other bacteria which upsets the natural balance of the vaginal microbiome.

Researchers from Monash University and Bayside Health's Melbourne Sexual Health Center published a landmark study in the New England Journal of Medicine in 2025, showing treating male partners reduces BV recurrence in women by more than 60 per cent.

The discovery reshaped international thinking on the condition and won this year's Australian Infectious Diseases Research Centre Eureka Prize for Infectious Diseases Research.

Their latest study, published in The Lancet Obstetrics, Gynaecology & Women's Health, builds on the original finding to reveal why some women continue to experience a repeat diagnosis of BV even when their male partners are treated concurrently, identifying two distinct pathways to repeat infection: re-infection and persistence of BV-bacteria.

Lead author Dr Lenka Vodstrcil, a Senior Research Fellow at Monash University and Bayside Health's Melbourne Sexual Health Center, said this has enabled them to work on tailoring treatments that will improve cure rates for millions of women worldwide.

While partner treatment improves cure for most women in a monogamous relationship, there are some women who have persistent BV-bacteria that survive initial therapy before couples resume sex after treatment. 

By identifying this early, we can intervene with more intensive female-focused treatments before the infection takes hold again."

Dr. Lenka Vodstrcil, Senior Research Fellow, Monash University

Senior author Vice-Chancellor's Distinguished Professor Catriona Bradshaw, clinician scientist and Head of Research Translation and Mentorship at Monash University and Bayside Health's Melbourne Sexual Health Centre, said the new approaches to treatment that are being trialed by her team include longer duration and new combinations of antibiotics designed to eradicate persistent BV-causing bacteria.

"Using partner-treatment to mitigate re-infection and more intensive strategies that target persistence of BV-bacteria, we hope to create more effective treatment approaches that can be tailored to an individual and achieve higher levels of cure for all women," Professor Bradshaw said.