Bacterial vaginosis is a condition which occurs when the normal balance of bacteria in the vagina becomes disrupted. This can result in an over-growth of certain bacteria, which is often accompanied by unpleasant symptoms.

Women with bacterial vaginosis may be at increased risk of infection with HIV. There is also good evidence that HIV-positive women who have bacterial vaginosis when they give birth are at greater risk of passing on HIV to their baby.

Washing the vagina (douching) is a common cause of bacterial vaginosis. Douching too frequently, or with too much soap, can upset the balance of bacteria. Use of spermicides, or strongly scented soaps and wearing tight, non-absorbent underwear have also been associated with an increased risk of bacterial vaginosis.

Although bacterial vaginosis is sometimes referred to as a sexually transmitted infection and is a very common condition amongst women attending sexual health clinics, this classification is not strictly speaking correct. You do not 'catch' bacterial vaginosis as it is not caused by particular bacteria which are usually transmitted sexually, such as gonorrhoea or chlamydia. Having a new sexual partner or multiple sexual partners, however, can also put women at increased risk of developing bacterial vaginosis.

Many women with bacterial vaginosis have no symptoms at all. When they do occur, symptoms can include a grey or whitish discharge from the vagina, which can have a fishy smell. Other symptoms can include itching around the vagina and a burning pain after passing water.

If bacterial vaginosis is left untreated, it can cause more serious symptoms and even lead to infertility or a potentially serious condition called pelvic inflammatory disease.

A general sexual health check-up will include tests for bacterial vaginosis. A doctor or nurse will examine you to look for signs of bacterial vaginosis and other sexually transmitted infections. A swab will probably be taken from the vagina and will be examined under a microscope to see if you have bacterial vaginosis or any other infection.

Sexual health screens are freely available from NHS genitourinary medicine (GUM) and sexual health clinics. Many HIV clinics also provide sexual health screens and tests for bacterial vaginosis as part of their routine care.

If you are pregnant, you should be screened for bacterial vaginosis and sexually transmitted infections as part of your routine care.

Having bacterial vaginosis can increase the chances that a woman will become infected with HIV if she is exposed to the virus. Women with bacterial vaginosis may be more likely to pass on HIV during sex to an HIV-negative partner as it can cause immune changes in the vagina. There is also evidence that HIV-positive women with bacterial vaginosis have a greater risk of infecting their baby during delivery.

Untreated bacterial vaginosis has also been associated with a risk of premature delivery and later infertility. Pelvic inflammatory disease, which is potentially very serious, can also occur if bacterial vaginosis is left untreated.

Although bacterial vaginosis sometimes goes away by itself as the balance of bacteria in the vagina corrects itself, it is important that HIV-positive women who believe that they may have the condition are screened for it and if necessary take treatment. It is particularly important that women who are pregnant or thinking about pregnancy are investigated and, if necessary, are treated.

Treatment is with antibiotics. Metronizadole can be used as an oral treatment. Treatment usually lasts for seven days and consists of twice-daily doses of 400mg. An alternative oral metronizadole treatment is a single 2g dose. Another possible treatment is an antibiotic gel that is put into the vagina. Metronizadole is available in a gel formulation, as is an antibiotic called clindamycin. It’s important that you take all the treatment prescribed to you.

Bacterial vaginosis can recur after treatment so you may require another course of treatment at a later date.