Long Considered a Female Problem, It's Actually an STI

About one in three women globally will get bacterial vaginosis (BV), a vaginal infection triggered by an imbalance in bacteria, and treatment isn't straightforward. It typically involves a week of antibiotics, but 50% of women will become infected again, says Lenka Vodstrcil, an expert in women's sexual health at Australia's Monash University. That could soon change. When Vodstrcil and colleagues decided to treat both infected women and their sexual partners, the recurrence rate fell by 60%, CNN reports. "The bacteria that cause BV can be located in men, especially in penile skin and also in the urethra," says Vodstrcil. "This suggests that BV is probably sexually transmitted."

The trial involved 164 heterosexual, monogamous couples in which the female partner had BV. Across 83 couples, only the woman took an oral antibiotic for a week. Across the other 81 couples, both partners took oral antibiotics, while the male partner also applied a topical antibiotic to the penis twice per day. There were few to no side effects, according to the study published Wednesday in the New England Journal of Medicine. Ultimately, the trial was ended early when it became clear that 35% of women experienced reoccurrence after both partners were treated, compared to 63% who received treatment alone, per the Guardian.

Trials in the 1980s and '90s concluded BV wasn't an STI because giving men oral antibiotics failed to reduce reoccurrence rates, per the New York Times. Researchers now say oral and topical treatments are key. The Melbourne Sexual Health Centre changed its BV treatment protocols in response, and researchers hope other facilities follow suit. An editorial accompanying the study notes treating BV as an STI would be a "paradigm shift," requiring men to share the responsibility for transmission and treatment with women. BV symptoms don't always appear but may include increased or smelly discharge and a burning or itching sensation. Infected patients are at greater risk of other STIs and pelvic inflammatory disease, as well as birth complications when pregnant. (More sexually transmitted infections stories.)