Bacterial Vaginosis - Sex Matters

Some pieces of research completely change the way we think about a condition; some also completely change the way we manage a condition. 

There are plenty of examples in recent years – think formoterol/steroid inhalers for asthma, SGLT2i for heart failure, GLP1ra for basically everything – but the conditions that get the most (media) attention tend to be for the ‘big’ conditions, like cancer and heart disease. One of the delights of general practice is that we can offer patients help with some of the ‘smaller’ conditions, which perhaps won’t kill them but still have an important, deleterious effect on life. 

And so it is with Sky. She is on the triage list because she has an offensive, fishy, grey vaginal discharge. It’s not the first time – she’s been diagnosed with bacterial vaginosis many times and already had treatment twice in the past few months. She has taken the prescribed treatment to the letter, but still it has returned. 

You ask all the usual questions – have you been vaginal douching (“No! Who does that?”… probably no-one but we still ask it every time…), bath additives (“I’m fresh out of bubble bath…”) or any new sexual partners (“No, I’m happily married, thank you”). 

So why is it coming back? It’s because we’re focusing on the patient, when we should be focusing on the partner.

We all know that bacterial vaginosis is a female problem. It’s perhaps surprising that we still don’t really understand the pathophysiology of this condition considering it affects around 30% of women worldwide. Characterised as dysbiosis of the vaginal microbiota, no single causative microbe has been found. This has led to it being classed as a non-sexually transmitted infection, but being sexually active is a risk factor and condom use is protective. Something doesn’t add up. BASHH guidelines for BV were last updated in 2012, thirteen years ago, and it acknowledges that even then there was debate about whether it could be considered an STI.

A group of Australian-based researchers aimed to settle the debate. Thirteen years later, published in March 2025 in the New England Journal of Medicine, their trial recruited  women with bacterial vaginosis who were in a monogamous relationship with a male partner. All women received first line antimicrobial agents but were randomised in to two groups: a control group (N = 83) where their partners had standard management with no treatment, and the active group (N = 81) where the male received oral and topical antimicrobial therapies, metronidazole 400mg tablets and topical 2% clindamycin cream, both used twice daily for 1 week.

Oral and topical treatment sound like overkill? Previous research found a lack of benefit from using either oral or topical agents, and the researchers explain that oral therapy can fail to clear external penile organisms while topical therapy may not eradicate urethral colonisation.

The numbers of participates in the trial may sound quite small, but this was because recruitment was stopped due to the overwhelming demonstration of efficacy from the treatment. Recurrence at 12 weeks post-treatment occurred in 35% of the active group but 63% of the control group.

Adverse events such as nausea, headache and vaginal itch were reported equal numbers between active and control groups, and fewer side effects were reported in men. Redness or irritation of the penile skin occurred only rarely.

The linked editorial highlights this data provides “substantial evidence supporting the role of sexual transmission of bacterial vaginosis-associated bacteria, particularly within regular sexual partnerships” and the need “for a major change to the treatment approach” and “to engage their male partners in sharing responsibility for transmission and treatment”.

This is one of those times when we need to completely reconsider how we think about a condition and it’s treatment. Ignoring this data fails our female patients. While UK guidelines will take time to change, if we have a female patient with recurrent BV and a regular male partner this data supports offering combination oral and topical antimicrobials to that partner. It may be what finally breaks the cycle.

This is not the only recent advance in our understanding of women’s health conditions. If you want to know more, join us on Friday 20^th June for our live Hot Topics Women’s Health for Primary Care webinar, with a full day problem updating us on the latest research and guidance in women’s health.