Also known as BV
Quick facts
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Healthy vaginas are protected by bacteria called lactobacilli that work to maintain an acidic pH in the vagina, prevent harmful bacteria from causing genital infections, and support healthy pregnancies.
Bacterial vaginosis (BV) develops when vaginal lactobacilli are replaced by BV-causing bacteria, which disturb the healthy vaginal environment.
BV affects up to 1 in 3 people with a vagina. BV may cause an unpleasant vaginal odour, vaginal discharge, or sometimes can cause no symptoms at all.
Once the healthy vaginal environment is disturbed by BV-causing bacteria, the vagina becomes more vulnerable to other sexually transmitted infections and complications.
BV infections usually only affect people who are sexually active. BV-causing bacteria can be transmitted through sexual contact.
Importantly, BV-causing bacteria can be carried on the penis, specifically on the penile skin and inside the urethra (the tube that urine and semen exit through). During penile-vaginal sex these bacteria can be transmitted from the penis to the vagina where they can cause a BV infection.
There is also evidence that BV-causing bacteria can be exchanged during sex between partners where both have a vagina.
Certain practices are associated with an increased risk of developing BV, including:
In addition, people who have a regular or ongoing sexual partner are more likely to get BV back again after treatment.
If you have BV, you may experience:
BV-causing bacteria do not usually cause symptoms in or on the penis; however, some people notice an unpleasant odour on their penis (sometimes described as a “fishy” odour).
Vaginal BV infections are diagnosed by a physical examination followed by laboratory testing.
Tests to detect BV-causing bacteria on the penis are not currently available.
BV is usually treated with an oral antibiotic or an intravaginal antibiotic cream for 5-7 days.
Due to the sexual transmissibility of BV, it can be helpful to involve regular sexual partners in treatment. Giving BV antibiotics to regular sex partners aims to treat and eliminate any BV-bacteria they may be carrying, which reduces the risk of reinfection. This strategy is most effective when both partners start and finish their antibiotics at the same time.
BV partner treatment is now available at the Melbourne Sexual Health Centre.
For regular sexual partners with a penis:
For regular sexual partners with a vagina:
More information about partner treatment can be found here: Bacterial vaginosis general information
Talk to a healthcare professional to discuss the best treatment option for you.
BV is a common and treatable infection and many people with BV do not suffer from any long-term complications.
If you have a vagina and uterus:
BV can increase your risk of other sexually transmissible infections, including chlamydia, gonorrhoea and HIV.
BV can increase the risk of pelvic inflammatory disease (PID), a condition that can cause pelvic pain and may lead to complications including infertility.
During pregnancy, BV has been linked to complications such as miscarriage, premature delivery and low birth weight of infants.
People who have an untreated regular sex partner are at higher risk for recurrent BV infections. A major reason for this is the carriage of BV-bacteria on the genitals of untreated partners, which gets transmitted back into the vagina during sex and causes reinfection. A recent clinical trial in monogamous couples where one partner has a penis has shown that partner treatment significantly improves long-term BV cure and reduces BV recurrence. Further research investigating the benefits of partner treatment in LGBTQIA+ couples is now underway.
A longer course of vaginal antibiotics, a combined treatment of oral and intravaginal antibiotics, or the addition of boric acid suppositories may also improve cure for persistent BV infections.
If your symptoms come back after treatment, see your doctor to discuss the best option for you.
Use barrier protection such as a condom (or dental dam) during sex.
Avoid douching or using any water, soaps or “feminine washes” inside the vagina. These are harmful to the “good” bacteria (known as lactobacilli) that protect the vagina.
Disclaimer
This fact sheet provides general sexual health information and is not intended to replace the need for a consultation with your doctor.
If you have concerns about your health, you should seek advice from your doctor.
If you require urgent care, you should go to your nearest Emergency Department or call 000.
