- BV affects 29.2% of U.S. women aged 14-49, making it one of the most usual vaginal infections.
- Studies show BV-associated bacteria can persist in the male genital tract, suggesting potential male-to-female transmission.
- While not classified as an STI, research suggests BV may need reclassification due to sexual transmission patterns.
- Untreated BV increases STI risk, pregnancy issues, and chronic vaginal health problems.
- Treating male partners and improving prevention strategies could reduce BV recurrence.
What Is Bacterial Vaginosis (BV)?
Bacterial vaginosis (BV) is a typical vaginal infection caused by a imbalance in vaginal microbiota. Ordinarily, the vaginal ecosystem is dominated by helpful Lactobacillus bacteria, which aid in maintaining an acidic pH and prevent harmful microorganisms from growing. However, when these good bacteria are outnumbered by anaerobic bacteria like Gardnerella vaginalis, BV can happen.
Common Symptoms of BV
BV can sometimes be without symptoms, but when symptoms do occur, they often include
- A thin, grayish or white vaginal discharge
- A persistent “fishy” odor, particularly after sexual intercourse
- Mild irritation or itching around the vagina
- A burning feeling while urinating
Risk Factors for BV
BV isn’t a traditional STI, but sexual activity does influence its occurrence. Some key risk factors include
- Multiple or new sexual partners: Disrupting vaginal flora through new bacterial exposure
- Douching: Removes protective Lactobacillus, altering vaginal pH
- Lack of Lactobacillus dominance: A less acidic vaginal environment promotes harmful bacterial overgrowth
- History of BV: Increases risk of recurrence
BV is also one of the most usual vaginal conditions in the U.S., affecting roughly 29.2% of women aged 14-49 (Koumans et al., 2007).
The Role of Bacteria in BV
The vaginal microbiome is a delicate ecosystem primarily maintained by Lactobacillus species, which produce lactic acid and hydrogen peroxide to keep harmful bacteria under control. When this balance is disrupted, anaerobic bacteria such as Gardnerella vaginalis, Atopobium vaginae, and Prevotella species can flourish, leading to BV.
Sexual activity, antibiotic use, hormonal changes, and hygiene practices can all impact this bacterial balance, contributing to BV development.
New Research: Evidence of Male Transmission
Until recently, BV was believed to occur independently of male involvement. However, new research suggests that male partners may act as sources of BV-related bacteria, increasing a woman’s likelihood of recurrent BV.
Key findings from recent studies (Muzny & Łaniewski, 2020)
- BV-related bacteria have been detected in the penile microbiomes of male partners of women with recurrent BV.
- Men who have unprotected sex with women with BV often carry BV-associated microbes in their genital tract.
- Women in monogamous relationships, where the male partner harbors BV bacteria, experience recurrent infections despite successful antibiotic treatment.
These findings indicate that BV may be sexually transmissible, at least in some cases, despite not being classified as an STI. However, more research is needed to determine whether treating male partners could improve BV results in affected couples.
Is BV a Sexually Transmitted Infection (STI)?
BV does not fit the traditional STI definition for several reasons
- It can occur without sexual activity – Some women develop BV independently of heterosexual intercourse.
- It is caused by an imbalance, not a single pathogen – Unlike STIs like chlamydia or gonorrhea, BV results from microbiome shifts.
- It does not trigger a standard immune response – Traditional STIs provoke a stronger immune reaction.
However, the discovery that men can harbor and potentially transmit BV-related bacteria has led some researchers to propose reclassifying BV as a sexually associated condition rather than a purely non-sexual infection.
What would change if BV were classified as an STI?
- Male partners may need testing and treatment.
- Prevention guidelines may emphasize condom use more strongly.
- Public health education could shift to acknowledge male-to-female transmission.
While no official reclassification has occured, ongoing research may challenge current medical understandings.
Health Risks of BV
Though BV may seem like a mild inconvenience, untreated BV can lead to serious health problems, including
- Increased STI susceptibility: A disrupted vaginal microbiome makes women more vulnerable to infections like HIV, chlamydia, and HPV.
- Pregnancy issues: BV has been linked to premature birth, low birth weight, and an increased risk of miscarriage.
- Pelvic inflammatory disease (PID): If BV-associated bacteria ascend the reproductive tract, they can cause PID, leading to infertility and chronic pelvic pain.
Given these risks, recognizing and addressing BV promptly is crucial for reproductive health.
How This Research Changes BV Prevention and Treatment
If BV can be transmitted by male partners, treatment approaches may need to change. Current strategies focus only on treating the woman, but new approaches could include
Treating Male Partners
- Some researchers propose treating male sexual partners of women with recurrent BV to reduce the risk of reinfection.
- Currently, male treatment for BV is not standard medical practice, but future studies may influence guidelines.
Current Treatment Options
- The most common antibiotics used to treat BV are metronidazole and clindamycin, available in oral or vaginal forms.
- Recurrence is common, so probiotic supplements (Lactobacillus species) may help restore vaginal flora balance after antibiotics.
Effective Prevention Strategies
Given BV’s potential sexual transmission, adopting preventive habits is key
- Using condoms or dental dams – Reduces exposure to foreign bacteria.
- Avoiding douching – Prevents disruption of beneficial vaginal bacteria.
- Taking probiotics – May help maintain a healthy vaginal microbiome.
Addressing BV Stigma and Misconceptions
BV is often surrounded by misinformation, which can lead to unnecessary embarrassment and delayed treatment.
Common Myths vs. Facts
“BV is caused by poor hygiene.” → False. BV is a bacterial imbalance, not a cleanliness issue.
“Women with multiple partners are the only ones who get BV.” → False. Monogamous women and even virgins can develop BV.
“BV isn’t serious and will go away on its own.” → False. BV can lead to reproductive health issues if untreated.
By normalising conversations about BV, we can reduce stigma and encourage timely medical care.
Practical Steps: What Should You Do If You Have BV?
If you suspect you have BV, taking proactive steps can aid manage and prevent recurrence
- See a doctor – BV is diagnosed through vaginal swab tests. Early treatment prevents complications.
- Discuss BV with your partner – If recurrent, consider discussing male involvement and potential treatment with your doctor.
- Adopt preventive habits – Using protection, taking probiotics, and maintaining vaginal health can lower recurrence risk.
Final Thoughts
New research is reshaping our understanding of BV, particularly regarding potential male-to-female transmission. While BV is not officially classified as an STI, evidence suggests that male partners can contribute to its recurrence, highlighting the need for further studies.
For individuals who experience persistent or recurrent BV, discussing treatment options with a healthcare provider and adopting preventive strategies can make a significant difference.
As our knowledge grows, so too must our approach to BV prevention, treatment, and education.
Citations
Koumans, E. H., Sternberg, M., Bruce, C., McQuillan, G., Kendrick, J., Sutton, M., & Markowitz, L. E. (2007). The Prevalence of Bacterial Vaginosis in the United States, 2001–2004; Associations With Symptoms, Sexual Behaviors, and Reproductive Health. Sexually Transmitted Diseases, 34(11), 864-869. https://doi.org/10.1097/OLQ.0b013e318074e565
Muzny, C. A., & Łaniewski, P. (2020). The Role of the Male Genital Microbiome in Bacterial Vaginosis: A New Frontier in Sexually Transmitted Infection Research. Clinical Infectious Diseases, 71(6), 1695-1705. https://doi.org/10.1093/cid/ciz962
Brotman, R. M., Shardell, M. D., Gajer, P., Fadrosh, D., Chang, K., Silver, M. I., … & Ravel, J. (2018). Association Between the Vaginal Microbiota, Menopause, and Estrogen Therapy in Postmenopausal Women. The Journal of Infectious Diseases, 217(4), 605-613. https://doi.org/10.1093/infdis/jix594
