A new study provides strong evidence that bacterial vaginosis, a common vaginal condition, is spread during sex

Is Bacterial Vaginosis an STI? Researchers Say Yes—Here's Why It Matters But experts are still debating about whether to officially call it an STI

• New research suggests that bacterial vaginosis, a common vaginal condition, might actually be an STI.
• The study found that treating both men and women in a couple for the condition led to far fewer reinfections than just treating the woman—which is the current practice.
• While the research provides strong evidence that bacterial vaginosis is spread during sex, experts are still debating whether to officially classify it as an STI.

Bacterial vaginosis, one of the most common vaginal conditions worldwide, might actually be a sexually transmitted infection after all. 

That’s the message from the authors of a new study published last week in The New England Journal of Medicine, the findings of which could have implications for who is treated for the condition and the type of medication they receive.

Bacterial vaginosis, or BV, is characterized by an imbalance of bacteria in the vagina and affects about 30% of reproductive-aged women in the U.S. The infection can lead to serious complications, including an increased risk of catching other STIs and developing pelvic inflammatory disease.

Women with BV are typically treated with a week of antibiotics, taken orally or topically, but the condition has a high resurgence rate—up to 80% of women get the infection again within nine months after treatment.

Given the high odds of reinfection, researchers decided to test a different strategy: treating both the woman and her male sexual partner for BV. They found that this led to much higher cure rates than the current practice of only treating the woman.

"We, and others, have accumulated a body of evidence to show that BV, and BV-associated bacteria, is sexually transmitted," study authors Lenka Vodstrcil and Catriona Bradshaw, researchers from Monash University and Melbourne Sexual Health Centre, Alfred Health, told Health in an email.

What is BV?

BV occurs when there is an imbalance of "good" and "bad" bacteria in the vagina, according to the Centers for Disease Control and Prevention.

"Normal flora of the vagina has bacteria that help keep the vagina healthy, but in BV, other types of bacteria take over," Aparna Sridhar, MD, an associate clinical professor of obstetrics and gynecology at the David Geffen School of Medicine at UCLA, told Health in an email.

While many women with BV don't have symptoms, those who do may experience:

• A thin white or gray vaginal discharge
• Pain, itching, or burning in the vagina
• A strong fish-like odor, especially after sex
• Burning when peeing
• Itching around the outside of the vagina

Why BV Isn't Classified As An STI

The cause of the bacterial imbalance that triggers BV isn't fully understood, and the American College of Obstetricians and Gynecologists (ACOG) doesn’t currently classify the condition as an STI—an infection that's spread by sexual contact. 

However, the infection rarely occurs in people who have never had sex, and previous research suggests that the risk of developing BV increases if you're sexually active. 

Some studies have also found BV-associated bacteria in men both within the urethra and on the penile skin, suggesting that the infection may be exchanged between partners during sex.

Despite this evidence, a few factors have prevented BV from being considered an STI. 

First, although it’s uncommon, people can develop BV without having sex. To some experts and organizations, that means you can’t officially call BV an STI. Also, men do not typically show any symptoms of BV. Finally, studies from the 1980s and '90s that treated BV in both sexual partners failed to prevent reinfection. 

Experts took the finding as evidence that BV is not an STI, but the studies had an important limitation: They only treated men with an oral antibiotic, not a topical ointment. 

"The body of evidence suggesting BV was sexually transmitted was overwhelming, so we decided we had to revisit partner treatment," Lenka and Bradshaw said. "We decided a new intervention, targeting both penile sites, is worth revisiting."

Investigating a New Treatment Strategy

The study included 164 monogamous heterosexual couples, and all of the female participants had BV. The couples were split into two groups. In one group, only the women received treatment for BV. In the other, the women received treatment along with the men, who took an oral antibiotic and used a topical cream.

After 150 couples completed the 12-week follow-up period, the trial ended early because the treatment of both partners far outperformed the women-only treatment. 

In the female-only treatment group, 63% of the women became reinfected with BV. Meanwhile, only 35% of women experienced a resurgence in the partner treatment group. 

"Our trial found that reinfection from an ongoing sexual partner is a significant driver of BV recurrence," the researchers said, “and by adding male partner-treatment to the treatment of women, we now have a simple strategy to reduce BV recurrence."

It's worth noting that the study only followed women in a monogamous relationship with a male partner, meaning the treatment may not be effective for women with multiple sexual partners.

Also, the trial was conducted in Australia, and most study participants were born in the Western Pacific and European regions. The researchers noted that BV prevalence differs by geographic region and ethnic group, so the findings may not be generalizable to all settings.

Will The Study Change the Way BV is Classified and Treated?

While the research is interesting, Sridhar said it's too soon to classify BV as an STI. 

"At this time, the study provides valuable evidence suggesting that treating male partners in heterosexual relationships may help reduce BV recurrence, but it does not definitively classify BV as a sexually transmitted infection," Sridhar said. "If BV were strictly an STI, it would not explain cases occurring in individuals who have never been sexually active." 

Still, the research provides evidence that BV can transfer through sex, said Gale Burstein, MD, MPH, FAAP, a professor of pediatrics at the Jacobs School of Medicine and Biomedical Sciences at the University of Buffalo and the commissioner for the Erie County Department of Health.

"Significantly reducing the prevalence of BV recurrence by treating the male sexual partner provides robust evidence that BV-associated bacteria are sexually transmitted," she told Health in an email.

"Healthcare providers already treat sexual partners of patients infected with gonorrhea, chlamydia, and trichomonas to prevent reinfection in the patient," Burstein added. "This new BV treatment strategy adds to our ability to prevent STI reinfections by treating asymptomatic sexual partners."

Shridhar also said the study will make her consider partner treatment for BV patients in heterosexual couples. Still, she's waiting for professional organizations, like the ACOG, to make official treatment recommendations.

Lenka and Bradshaw would like to see that happen. In the meantime, they’ve developed a website that shares the new research, informs doctors about their recommended course of treatment, and provides information that could help people discuss BV with their partners. 

"We recognize that for men who don’t have symptoms, taking medication can be confusing," the researchers said. "But through this study, we have shown that treating BV can be seen as a shared responsibility."

Edited by Health with a background in health, science, and investigative reporting. Previously, she wrote full time about parenting issues for the app Parent Lab. Before that, she worked as a reporter for National Geographic covering wildlife crime and exploitation." tabindex="0" data-inline-tooltip="true"> Jani Hall Jani Hall Jani Hall is a news editor for Health with a background in health, science, and investigative reporting. Previously, she wrote full time about parenting issues for the app Parent Lab. Before that, she worked as a reporter for National Geographic covering wildlife crime and exploitation. learn more

This story originally appeared on: Health News - Author:Jenna Anderson