BV explained
Bacterial vaginosis (BV) is a very common vaginal infection that affects 1 in 3 women and other people with a vagina worldwide. BV is associated with an imbalance in the bacteria within the vagina. Vaginas contain large amounts of ‘good’ or ‘optimal’ bacteria, which work to keep the vaginal environment healthy and balanced. Similar to the way the bacteria in the gut (known as the gut microbiome) are important for gut health, the vaginal microbiome is an important part of vaginal health.
BV is caused when a group of ‘bad’ or ‘non-optimal’ bacteria (BV-bacteria) take over the vaginal microbiome, which disrupts the healthy balance of ‘good’ bacteria and causes symptoms. Increasingly, research suggests that BV-bacteria can be sexually transmitted, which means that sexual partners and sexual practices play a role in acquiring BV and BV coming back after treatment.
BV is treated with antibiotics prescribed by a doctor. Though these antibiotics are very effective in the short term, BV often comes back within just a few weeks or months of finishing treatment. We have shown that more than 50% of people with BV experience recurrence within 6 months of treatment.
Causes
BV is caused when one or more BV-bacteria disrupt the healthy balance of the vaginal microbiome.
Sexually active people are more likely to get BV. Previously, it was unclear whether BV was transmitted through sex, or whether sexual activity itself was causing BV. New evidence show that BV-bacteria can be detected on the penis and be transmitted through unprotected sexual contact.
Risk factors
Certain practices are associated with an increased risk of developing BV, including:
- having a new sexual partner
- having unprotected penile-vaginal sex (sex without a condom)
- having a sexual partner with a vagina
- having sex with a partner with an uncircumcised penis
- vaginal douching (washing inside the vagina with water, soap, “feminine wash”, etc.)
- having an intrauterine device (IUD), particularly a copper IUD
In addition, people who have a regular or ongoing sexual partner are more likely to get BV back again after treatment. This indicates that people are getting reinfected from their sexual partner.
Lowering your risk of BV
Use of a barrier method, like a condom, during sex may help to prevent BV, although barrier methods are not completely protective.
You can support a healthy vaginal environment by avoiding douching or using any water, soaps or “feminine washes” inside the vagina. These products are detrimental to the “good” bacteria (known as lactobacilli) that live in a healthy vagina.
Signs and symptoms
Symptoms of BV include:
- strong or unpleasant vaginal odour
- increase or change in vaginal discharge (thin consistency, white/grey)
- vaginal discomfort
Not everyone with BV has symptoms; many BV infections are asymptomatic. You may have all, or none, of the symptoms listed above. Studies suggest that the onset of symptoms usually begins approximately 5 days after sex.
Most partners who have a penis and are carriers of BV-bacteria will be asymptomatic, although some may notice that their penis has a fishy malodour.
Untreated BV
BV is a common and treatable infection and many people with BV do not suffer from any long-term complications. However, BV has been linked with pelvic inflammatory disease (PID) and an increased risk of contracting a sexually transmitted infection, including HIV. During pregnancy, BV may increase the risk of miscarriage, premature delivery and low birth weight of infants.
Testing and diagnosis
BV is diagnosed by a combination of a physical examination and laboratory tests. Currently, testing is only available for detecting vaginal BV infections. Routine testing is not currently available to determine if BV-bacteria are present on the penis.
Treatment and recovery
BV is usually treated with an oral antibiotic or a vaginal antibiotic gel or cream for 5 to 7 days.
For many people these treatments will clear the BV infection in the short-term. However many people, particularly those with a regular sexual partner, experience a repeat BV infection shortly after completing their antibiotics.
There are two reasons for this.
- BV recurrence
- BV persistence
BV recurrence is most common in individuals with an ongoing sexual partner and is due to reinfection with BV-bacteria from the untreated partner. To prevent this from occurring, partner treatment options are now available. Partner treatment needs to be taken at the same time as the person diagnosed with BV is being treated.
BV persistence can be hard to distinguish from BV recurrence but is most obvious in a person without an ongoing partner. For individuals where reinfection is unlikely, a longer course of vaginal antibiotics, or a combination of oral and vaginal antibiotics, or the addition of boric acid suppositories can be used as treatment strategies.
If your BV symptoms come back after treatment, see your doctor to discuss your options.
Getting help
When should I see my doctor?
If you are experiencing any symptoms or have had sexual contact with someone diagnosed with BV, talk to a healthcare professional about BV testing and treatment options.
We acknowledge that our research may not fully reflect the diversity of the community we aim to support, including intersex populations. We encourage individuals in these groups to discuss their needs with their clinician to determine the most appropriate care.