A Third of Women Get This Infection. The Fix: Treat Their Male Partners.
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Common vaginal condition is really an STD, study finds
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A common but potentially dangerous vaginal infection that affects nearly 1 in 3 women globally should be considered a sexually transmitted disease, a new study says.
Bacterial vaginosis, or BV, is currently viewed as a woman’s issue, thus leaving the sexual partner untreated.
“I started getting them quite recurrently. I’d go to doctors and get treated with antibiotics, and it would almost always come back,” said Hanae, a woman who participated in the clinical trial on BV conducted in Melbourne, Australia.
“It’s like not really worth it for me to even go to doctors,” said Hanae, whose last name was withheld by the study authors to protect her privacy.
For half of all women with bacterial vaginosis, the infection returns after completion of a week of antibiotics, the preferred medical treatment for BV, said first author Lenka Vodstrcil, a senior research fellow at the Melbourne Sexual Health Centre at Monash University in Australia.
“The bacteria that cause BV can be located in men, especially in penile skin and also in the urethra,” Vodstrcil said in a news release. “This suggests that BV is probably sexually transmitted, and that is why so many women get it back again after treatment.”
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When BV was treated as a sexually transmitted disease, with both partners receiving oral antibiotics and men using topical creams, the recurrence rate dropped by over half, according to the study published Wednesday in the New England Journal of Medicine.
“Our trial has shown that reinfection from partners is causing a lot of the BV recurrence women experience, and provides evidence that BV is in fact a STI (sexually transmitted infection),” said senior author Catriona Bradshaw in an email. Bradshaw is a professor at the Melbourne Sexual Health Centre at Monash University.
Symptoms of BV can include itching, pain while urinating, an odd odor and a thin, white vaginal discharge. For some women, however, BV is a silent predator, attacking without such telltale symptoms.
If left untreated, bacterial vaginosis can increase the risk of acquiring HIV as well as sexually transmitted infections, according to the World Health Organization. Women with BV can also develop an infection in the fallopian tubes, ovaries or uterus called pelvic inflammatory disease, the WHO states on its website.
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Such infections can lead to later infertility, experts say.
“We see very significant changes in a range of inflammatory markers, inflammatory cells and bacterial enzymes and products that result in damage to the epithelium — the lining of the reproductive tract,” Bradshaw said.
Bacterial vaginosis is especially dangerous during pregnancy. The infection can lead to premature birth, spontaneous abortion and low birth weight in the baby, according to the WHO.
The randomized clinical trial of 164 monogamous couples was conducted at multiple centers in Australia. In 81 of the couples, both partners were treated with seven days of oral antibiotics. During that time, the male partner also used a topical antibiotic on their penis twice a day.
In accordance with current recommended treatment, only the woman in the other 83 couples was treated with an oral antibiotic.
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While the study only treated heterosexual couples, it’s “important to note that women in same sex relationships also transmit BV bacteria between each other during sex, and that these same sex couples in monogamous relationships have very high rates of concordance for BV — both have it or both don’t have it,” Bradshaw said.
The trial was meant to last for 12 weeks, but researchers stopped it early when it was quickly apparent that treating both partners reduced BV occurrence by 60%.
Viewing such a common vaginal infection as a sexually transmitted disease would be a “paradigm shift” and would require doctors to encourage a woman’s male partner to share responsibility for transmission and treatment, according to an editorial published alongside the study.
“It will also require a willingness of male partners to commit to taking both oral and topical medications, once notified by their female partner that she has bacterial vaginosis and that it is probably sexually transmitted,” wrote Dr. Christina Muzny and Dr. Jack Sobel, who were not involved in the new research.
Muzny is a professor of infectious disease at the University of Alabama at Birmingham. Sobel is a professor in the Division of Infectious Diseases at the Wayne State University School of Medicine in Detroit.
Men in the study had no problem completing the course of oral and topical antibiotics, with few to no side effects, the study found.
“We have now used this medication in close to 300 men and we have not had any report that side effects from the medication would stop them taking it,” Bradshaw said.
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The Melbourne Sexual Health Centre has already changed its protocols and are now treating both partners when BV is detected, Bradshaw added. For health professionals and couples interested in treating both partners, the research team develped a website that provides detailed information on male partner treatment.
“Changes in national and international treatment guidelines always take time, so we felt an obligation to provide accurate online and downloadable information,” Bradshaw said.
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A potentially dangerous infection
It’s time for a ‘paradigm shift’ in treatment
Treating Males for Bacterial Vaginosis May Reduce Recurrence in Females
Bacterial vaginosis (BV) is a common vaginal infection affecting nearly 1 in 3 females
globally with strong recurrence rates.
While the emphasis on treatment has focused on females, a new study suggests that sexual partners should also be treated for the condition that researchers say fits the profile of a sexually transmitted infection (STI).
BV infection may develop following exposure to a new sexual partner without a condom or other barrier method. Reinfection or recurrence following treatment is associated with exposure to a regular sexual partner.
During sexual intercourse, bacterial vaginosis-associated organisms are exchanged between partners, the researchers found.
When female and male sexual partners were treated for BV, recurrence rates were lower. Females received first-line antimicrobial agents, and males were administered combined oral and topical antimicrobial therapy. Researchers say this combination therapy contributed to the lower BV recurrence rates in females within 12 weeks.
These findings suggest that including male partners in treatment for BV could improve treatment success and potentially lead to a cure. The study was published on March 5 in The New England Journal of Medicine.
“Clinicians and researchers with similar views have undertaken partner treatment trials in the past, but none failed to reduce recurrence or improve BV cure for women,” said study co-author Catriona Bradshaw, PhD, of the Melbourne School of Population and Global Health at the University of Melbourne, Australia.
“This was in part due to trial limitations, but we also believe this may be because they all used oral antibiotics for men only,” Bradshaw told Healthline.
Although BV is both treatable and curable
, around 50% of females
experience recurrence within six months after antibiotic treatment, which may raise the risk of obstetric complications down the road.
When there is a regular sexual partner, the risk of BV recurrence increases three-fold.
Experts haven’t considered BV an STI because the bacteria typically originates
from within versus sexual transmission. However, as the new study points out, this isn’t always true.
Prior research has shown that men carry bacterial species linked to BV in the urethra and penis.
To show that BV fits the profile of an STI, researchers collected a body of evidence that Bradshaw described as a journey 20 years in the making.
The randomized controlled trial involved 164 heterosexual monogamous couples in which the female had bacterial vaginosis.
The partner-treatment group involved 81 couples. Female partners received first-line antimicrobial treatment, and male partners received combined oral and topical antimicrobial therapy (metronidazole 400-milligram tablets and 2% clindamycin cream applied to penile skin) twice daily for 7 days.
“We believed it was important to try and target the bacteria on the penile skin with a topical antibiotic cream as well as inside the urethra with an oral antibiotic,” Bradshaw explained. “This had never been done before.”
The control group had 83 couples, in which females received the same standard of care and males received no treatment. The primary outcome was BV recurrence within 12 weeks.
The trial was stopped at the 12-week follow-up mark because the female-only treatment was inferior to treating both partners.
In the both-partner treatment group, BV recurrence occurred in 35% of females compared to a 63% recurrence rate among females in the control group.
Adverse events in male partners receiving treatment were mild and included:
“We are relieved that this treatment strategy has been so effective,” Bradshaw said.
“It enables us to understand that reinfection of women with BV bacteria from men is responsible for a large proportion of BV recurrence in women. The treatment is easy and well tolerated and only needs to be taken for a week.”
Bradshaw noted that more studies in diverse populations and settings are needed to confirm the findings.
For instance, Bradshaw would like to further investigate what may be causing BV treatment failures and driving high recurrence rates.
She’s also curious why BV persisted among a smaller group of females who still had the infection after finishing their antibiotics even though they had not resumed sex, she explained.
Still, these findings could eventually pave the way for improved BV treatments involving both partners.
“Our program of research is focused on analyzing the samples from couples to understand if there are specific BV bacteria in men that are causing BV recurrence in women, which would help us develop better tests for BV, including something that has not been done before — a test for men,” Bradshaw said.
“We do hope that this trial helps clinicians individualize BV treatment for their patients. This trial is relevant to women in a current monogamous relationship with a male, but for women without a current partner, messaging needs to be more around treating them and understanding that condoms provide some protection against catching BV as they do for many STIs.”
To help increase awareness about treating BV as an STI, the researchers produced a website with resources for healthcare professionals, patients, and their male partners.
Bacterial vaginosis (BV) develops when there is a disruption to the balance of bacteria in the vagina, which leads to an overgrowth of certain bacteria.
BV causes uncomfortable symptoms such as:
Some individuals with BV may not experience any symptoms, which means regular gynecological visits are important for detection.
First-line treatments
for bacterial vaginosis usually include antibiotics that can be taken orally, or that may come in the form of a vaginal gel or suppository. These include:
When BV persists after first-line treatments, other approaches may include:
Contact a healthcare professional if you experience:
Bacterial vaginosis (BV) is not classified as a sexually transmitted infection, but the results of a new study could change that.
Evidence shows that BV occurs in males, and researchers at the University of Melbourne say that treating both partners could help lower high infection recurrence rates in females.
More studies in larger, diverse groups are needed to confirm these findings and better understand why some people with BV continue to resist treatment.
Our experts continually monitor the health and wellness space, and we update our articles when new information becomes available.
Current Version
Mar 10, 2025
Written By
Andrea Rice
Edited By
Angela Chao, MA
Fact Checked By
Jill Seladi-Schulman, Ph.D.
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