Should the male partner of a female patient diagnosed with Bacterial Vaginosis (BV) be treated for BV?

Should Male Partners Be Treated for Bacterial Vaginosis?

No, routine treatment of male partners is not currently recommended by CDC guidelines, though groundbreaking 2025 evidence suggests this may change. 1

Current Guideline Recommendations

The established CDC guidelines explicitly state that routine treatment of sex partners is not recommended for bacterial vaginosis. 1 This recommendation is based on the fact that treatment of sex partners in clinical trials has historically not influenced the woman's response to therapy, nor has it influenced the relapse or recurrence rate. 1

Key Rationale for Current Guidelines:

• Male partners are typically asymptomatic even when carrying BV-associated bacteria 2, 3
• The principal goal of BV therapy is to relieve vaginal symptoms in the affected woman, not to prevent transmission 2
• Previous randomized controlled trials of male partner treatment showed no uniform benefit 4

Critical New Evidence That May Change Practice

A landmark 2025 randomized controlled trial published in the New England Journal of Medicine fundamentally challenges current guidelines. 5 This Australian study (the StepUp trial) demonstrated that treating male partners with combined oral metronidazole (400 mg twice daily) and topical 2% clindamycin cream (applied to penile skin twice daily) for 7 days resulted in:

• 35% recurrence rate in the partner-treatment group versus 63% in the control group (P<0.001) 5
• Absolute risk reduction of 2.6 recurrences per person-year 5
• The trial was stopped early by the data safety monitoring board because treatment of the woman only was clearly inferior 5

Supporting Microbiological Evidence:

• A 2021 pilot study using 16S rRNA gene sequencing showed that concurrent partner treatment significantly reduced BV-associated bacteria at all three anatomical sites (vagina, penile skin, and male urethra) 6
• BV-associated bacteria suppression was sustained in 81% of women over 12 weeks 6
• Only 17% of women experienced recurrence within 12 weeks, substantially lower than the typical 50% recurrence rate 6

Important Limitations of Previous Studies

The six older randomized trials that formed the basis for current guidelines had significant methodological flaws: 4

• Randomization methods were either overtly deficient or insufficiently reported 4
• Five trials used suboptimal treatment regimens in women 4
• Adherence to treatment was poorly documented 4
• All six trials had limited statistical power 4
• None assessed whether antibiotic treatment affected the penile microbiota 4

Clinical Implementation Considerations

If You Choose to Treat Male Partners (Based on New Evidence):

Treatment regimen: 5, 6

• Metronidazole 400 mg orally twice daily for 7 days
• AND 2% clindamycin cream applied topically to the glans penis and upper shaft (under the foreskin if uncircumcised) twice daily for 7 days

Critical Safety Warning:

• Men must avoid alcohol during metronidazole treatment and for 24 hours afterward due to potential disulfiram-like reaction 2, 3

Adverse Effects in Men:

• Nausea, headache, and metallic taste were reported 5
• Generally well-tolerated with good adherence 6

Practical Approach for Clinicians

Current standard of care remains no partner treatment per CDC guidelines 1, but the 2025 NEJM trial provides compelling evidence for a paradigm shift. 5

When to Consider Partner Treatment:

• Women with recurrent BV (multiple episodes within 6-12 months) 5
• Women in monogamous relationships with male partners 5
• After discussing the new evidence and that current CDC guidelines have not yet been updated 2
• When both partners are willing and able to adhere to the 7-day regimen 6

Common Pitfalls to Avoid:

• Do not confuse BV with candidiasis (VVC), which does not require partner treatment 1
• Do not use metronidazole gel for male partners—the StepUp trial used oral metronidazole plus topical clindamycin 5
• Do not treat partners without ensuring alcohol avoidance counseling 2, 3
• Do not assume single-agent therapy will work—the successful regimen used combination oral and topical treatment 5