Bacterial vaginosis

What is bacterial vaginosis?

Bacterial vaginosis (BV) is a bacterial infection of the vagina. It occurs when there is an imbalance of the naturally occurring bacteria in the vagina (vaginal microbiome). It’s the most common type of vaginal infection in women of childbearing age, although women of any age can be affected. BV affects around 10% of women in Australia at some stage in their life.

Signs and symptoms of bacterial vaginosis

Around half of women with BV do not have symptoms. When symptoms do occur, they may include:

• watery, white, grey or greenish vaginal discharge
• an unpleasant or ‘fishy’ odour
• discomfort and itching
• burning sensation during urination.

What causes bacterial vaginosis?

A healthy vaginal microbiome consists of the right balance between ‘good’ and ‘bad’ bacteria. In this environment, Lactobacillus is the predominant ‘good’ bacteria. In BV, there is an overgrowth of what’s known as anaerobic bacteria (anaerobes) or other bacteria – the ‘bad’ bacteria.

While the exact cause of BV is unknown, several studies have identified sexual-related risk factors associated with BV. Women are more likely to experience BV if they:

• report multiple lifetime sexual partners
• have a new sexual partner
• practise unprotected sex
• have sex with other women
• practise douching, which washes out all the bacteria allowing the ‘bad’ bacteria to grow (a healthy vagina balances itself and maintains its own cleanliness)
• use an intrauterine device (IUD).

How is bacterial vaginosis diagnosed?

To diagnose BV, your doctor will take your medical history, which may include asking about your symptoms, whether you have had these symptoms before, and your sexual history including a past history of sexually transmitted infection (STI). Your doctor will perform a pelvic examination and take a vaginal swab to test for abnormal or an overgrowth of bacteria, or a pH test to check the acidity of your vagina.

Treating and managing bacterial vaginosis

Treatment for BV usually involves a course of antibiotics which can be taken by mouth, or in the form of a cream or gel to put in your vagina. You will need to take the full course of antibiotics, even if symptoms go away before the end of the course. Stopping treatment early may increase the risk of the infection coming back.

Because BV can reoccur with sexual contact, it’s recommended you avoid sexual contact until you have finished taking your medication, and symptoms have gone.

Generally, it’s not necessary to treat a male sexual partner. However, BV can spread between female sexual partners. If your partner is female, it’s important she see her doctor to check if she needs treatment.

Risks and complications

While treatment is usually effective, around half of women will experience a recurrence of BV within 12 months. If you notice new symptoms, be sure to visit your doctor for further treatment.

BV increases the risk of:

• pregnancy and birth issues, including premature deliveries, premature rupture of membranes, and low birth weight babies. It can also lead to an increased risk of chorioamnionitis (inflammation of the lining of the sac around the baby in pregnancy)
• sexually transmitted infections (STIs), such as HIV, herpes, chlamydia, or gonorrhoea
• post-operative infection related to gynaecological surgery such as dilation and curettage (D&C) or laparoscopy
• pelvic inflammatory disease (PID), which is an infection of the uterus, fallopian tubes and ovaries. This can lead to infertility.

When to seek help

BV symptoms can be similar to those of other infections, so it’s important to see your doctor if:

• your vaginal discharge has changed
• there is an unpleasant odour
• you have a fever
• your vagina or vulva is irritated
• you have multiple sex partners or a new partner (especially if you have had unprotected sex)
• treatment with an over-the-counter medication hasn’t resolved symptoms
• symptoms reoccur or persist even after seeing a doctor for treatment
• you have symptoms and are trying to get pregnant or are pregnant.

What you can do

Most cases of BV seem to be associated with sexual activity. Using condoms during sex has been shown to protect against infection. It’s also important to engage in safe sexual practices, regardless of the gender of your sexual partner.

Other things you can do include:

• Reducing the risk of vaginal irritation by avoiding any deodorants or perfumed products in and around your vagina (e.g. toilet paper, tampons, pads, soaps and washes). Use 100% cotton tampons or pads, white toilet paper and a soap substitute or water
• NOT douching, as this disrupts the vaginal microbiome and increases the risk of vaginal infection.

Remember, if you experience any unusual or new symptoms related to your vagina or vulva, see your doctor.

This web page is designed to be informative and educational. It is not intended to provide specific medical advice or replace advice from your health practitioner. The information above is based on current medical knowledge, evidence and practice as at November 2020.