Doctors find evidence of new sexually transmitted infection and believe millions of people already have it

A new study conducted by researchers in Australia has found a common infection that affects millions of people worldwide may actually be a sexually transmitted infection.

Bacterial vaginosis (BV) is not currently officially classified as an STI, but a new study published in the New England Journal of Medicine has suggested that maybe it should be, based on how STIs are defined.

According to the Cleveland Clinic, approximately 35 percent of people with a vagina will get BV, which is caused when a growth of bad bacteria in the vagina overtakes the good bacteria. It results in unusual, off-white-colored vaginal discharge and a 'fishy' smell, and can cause irritation in some people, but not everyone.

Only doctors can diagnose BV (Getty Stock Photo)

How can you develop BV?

Anyone with a vagina can get bacterial vaginosis, but it typically occurs in people who are sexually active.

There are a number of other factors that may contribute to an increased risk of BV, including pregnancy, IUDs, having multiple sexual partners, having a new partner, using douches or taking antibiotics.

People who don't use condoms or dental dams may also be at higher risk of developing the infection.

Why might BV be an STI?

In the study, conducted by Monash University and Alfred Health researchers at the Melbourne Sexual Health Centre, worked with 164 couples in which the woman had BV and was in a monogamous relationship with a male partner.

In half of the participants, men were given an oral antibiotic and a topical antibiotic cream to apply to the skin, rather than researchers treating solely the woman.

In the other half of the couples, the men were given no treatment.

Researchers found success when treating both men and women who had BV (Getty Stock Photo)

What the researchers found was that the cure rates were higher when both couples were treated, as would be the case with an STI.

Commenting on the findings, per BBC News, one of the lead researchers, Prof Catriona Bradshaw, said: "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 an STI."

Bradshaw added that the researchers faced difficulties in establishing whether BV is sexually transmitted because they don't know precisely which bacteria are the cause, but she added that advances in genomic sequencing may help them figure it out.

As a result of the findings, the Melbourne Sexual Health Centre has now changed its clinical practice to routinely treat both partners.

How is BV treated?

Only a doctor can diagnose BV, and if diagnosed they may prescribe antibiotics in the form of a gel or cream you insert into your vagina. Antibiotics may also come in the form of pills.