New Study Reveals Bacterial Vaginosis May Be Sexually Transmitted, Prompting Reclassification as STI

Urgent warnings are emerging from the medical community as new research reveals that bacterial vaginosis (BV), a condition affecting up to one in four women globally, may be transmitted during sexual activity. This revelation has sparked calls to reclassify BV as a sexually transmitted infection (STI), challenging long-held assumptions about its origins. BV occurs when the natural balance of vaginal bacteria is disrupted, often leading to symptoms like unusual discharge or a fishy odor, though many women remain asymptomatic. However, the implications of this condition extend far beyond discomfort, linking it to heightened risks of other STIs, pregnancy complications, and even cervical cancer.

The connection between BV and serious health outcomes has long been established. Studies have shown that BV increases susceptibility to infections such as chlamydia, gonorrhoea, and HIV, while also raising the risk of preterm birth and miscarriage. Perhaps most alarming is its role in facilitating the spread of human papillomavirus (HPV), the primary cause of cervical cancer. Now, new evidence suggests that sexual transmission may be a key driver of BV recurrence, prompting experts to reconsider its classification. Research published in recent years has demonstrated that treating male partners alongside women significantly improves treatment outcomes, indicating that BV-associated bacteria can be passed between sexual partners—even though men themselves do not develop symptoms.

Valentina Milanova, a leading expert in public and gynaecological health, has emphasized the growing consensus among medical professionals that BV should no longer be treated as an isolated condition. "The traditional argument against classifying BV as an STI is that it results from an overgrowth of endogenous flora rather than a single external pathogen," she explained. "But this argument is becoming increasingly difficult to defend in light of new findings." Milanova and her colleagues are urging healthcare systems to adopt a framework similar to that used for other STIs, including routine screening and treatment of both male and female partners to break the cycle of reinfection.

In countries such as the United States, Canada, and Australia, BV is already managed within sexual health frameworks in accordance with World Health Organization (WHO) guidelines. These protocols include treating partners and implementing preventive measures to reduce recurrence rates. However, the UK has lagged behind, with outdated guidelines from 2012 that do not reflect current evidence. As a result, clinicians in the UK are not routinely treating male partners, notifying sexual contacts, or conducting systematic screening. This gap in practice leaves many women vulnerable to repeated infections, which can have severe consequences. Recurrent BV has been linked to increased risks of HIV, HPV, and urinary tract infections, as well as reproductive complications such as preterm birth and miscarriage.

The need for updated prevention strategies is becoming increasingly urgent. A study conducted by researchers from Mass General Brigham and the Vaginal Microbiome Research Consortium explored innovative approaches to managing BV. In a trial involving 90 women with the condition, participants who took a daily probiotic containing beneficial bacteria after antibiotic treatment were significantly less likely to experience a recurrence. Some individuals saw improvements within just a few days, as the probiotic helped restore the vaginal microbiome's natural balance. Unlike antibiotics, which eliminate infection, this approach focuses on rebuilding a protective environment that discourages harmful microbes. Researchers suggest this method could have broader implications, including potentially reducing HIV transmission rates in high-prevalence regions.

Simple lifestyle adjustments may also play a role in preventing BV or reducing its recurrence. Experts recommend avoiding perfumed products, douching, and vaginal deodorants, as these can disrupt the vaginal microbiome. Washing with water or mild soap is preferred. Other risk factors include smoking, having multiple sexual partners, and using intrauterine devices (IUDs), all of which can alter the natural bacterial balance. Addressing these factors through education and public health initiatives could complement medical treatments and improve long-term outcomes.

As the evidence mounts, the call for action is clear: reclassifying BV as an STI and adopting comprehensive, globally aligned prevention strategies are essential to protecting women's health. The UK's outdated guidelines must be updated to reflect the latest scientific understanding, ensuring that both men and women receive the care needed to break the cycle of reinfection. With the right interventions, the burden of BV—and its associated risks—could be significantly reduced, offering hope for a future where this common condition no longer poses such a serious threat.