Common vaginal condition is really an STD, study finds

CNN

06-03-2025

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.'
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.
A potentially dangerous infection
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.
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.
It's time for a 'paradigm shift' in treatment
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.
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.
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 is developing 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.