Bacterial vaginosis - including symptoms, treatment and prevention

Bacterial vaginosis is the result of a major change in the types and numbers of bacteria usually found in the vagina. Changes in the normal acidity of the vagina are accompanied by an overgrowth of several different kinds of bacteria which are normally present in only very small numbers. These bacteria replace the normal protective vaginal bacteria (lactobacilli).

It used to be thought that bacterial vaginosis was caused by overgrowth of bacteria called Gardnerella vaginalis, but it is now recognised that these bacteria occur in many women who have no symptoms, and attempting to grow them from vaginal secretions is no longer recommended.

How bacterial vaginosis is spread

Bacterial vaginosis is not considered to be a sexually transmitted disease, although it is associated with sexual activity.

Signs and symptoms of  bacterial vaginosis

Symptoms include:

  • a greyish vaginal discharge
  • an unpleasant ‘fishy’ odour. The odour is often more noticeable after sex or during menstruation, when the acidity of the vagina changes.

Painful intercourse and genital itch do not commonly occur with this condition.

Diagnosis of  bacterial vaginosis

Diagnosis is made by a vaginal examination and a microscopic examination of a sample of the vaginal discharge.

Incubation period

(time between becoming infected and developing symptoms)

The cause is not yet understood, so the time between whatever changes cause bacterial vaginosis and development of symptoms is unknown.

Infectious period

(time during which an infected person can infect others)

Not transmitted to sexual partners.

Treatment for  bacterial vaginosis

Bacterial vaginosis is not usually treated unless symptoms are a problem. Several treatments are available, both vaginal creams and tablets. Women with bacterial vaginosis may be at slightly increased risk of complications in pregnancy and of developing infections after gynaecologic surgery and should discuss the need for treatment with their doctor.

Vinegar or Aci-Jel vaginal jelly help to relieve symptoms but are not useful for treatment or prevention.

Sexual partners do not need to be treated.

For more information on treatment options, see the Bacterial vaginosis brochure (PDF 103KB)

Prevention of  bacterial vaginosis

Avoid vaginal douching, use of shower gel, use of antiseptic agents and shampoo in the bath.