Bacterial vaginosis (BV)

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Bacterial vaginosis (BV) is caused by an overgrowth of certain types of bacteria, which results in vaginal inflammation.  With BV, there is a shift in the bacterial ecosystem, favouring the “not so good or healthy” type such as Gardnerella vaginalis, Mycoplasma hominis and Mobiluncus species and a corresponding reduction in the healthy types such as lactobacillus. There is also a disturbance of the vaginal pH. Bacterial vaginosis most often occurs during reproductive years. It is not regarded as a sexually transmitted infection, but sexual activity has been linked to the development of this infection.

Symptoms and signs

Approximately 50% of women with BV have no symptoms. The vaginal discharge usually has an unpleasant odour (referred to as a “fishy” smell). The colour may vary from grey, yellowish, or greenish and is usually more fluid compared to candida infection (yeast). The colour and amount vary greatly from woman to woman.

Risk factors

  • BV may be more common in women with an intra-uterine contraceptive device (IUD).
  • Multiple sexual partners, or a recent new sexual partner
  • Recent use of antibiotic medications.
  • Vaginal douching (cleaning of the vagina with a cleansing agent). This can upset the natural eco-system of the vagina.
  • Lack of natural lactobacilli bacteria in the vagina – the reasons for this is unclear.

Possible complications

  • BV may recur even after treatment.
  • Co-infection with another vaginal disorder may occur such as chlamydia or gonorrhoea.
  • May cause postoperative infection following hysterectomy and post-miscarriage pelvic infection.
  • The presence of BV during pregnancy may be associated with certain complications such as premature birth and low birth weight baby.


Diagnostic tests may include laboratory studies of vaginal discharge, cervical cytology smear (Pap smear/Thin Prep) and pelvic assessment. It is important to exclude other causes of vaginal discharge. Testing and treating male sexual partners is usually not recommended.


For some women without symptoms, the BV can resolve spontaneously. Treatment is usually recommended for women who have symptoms, women undergoing surgical procedures, and some pregnant women. Treatment with antibacterial medication for seven days provides a safe and effective cure. Avoid sexual intercourse until you have completed treatment and your symptoms are gone. Recurrence of BV is not uncommon even after treatment.  If that happens, another course of treatment is required.  If you use an intrauterine device and BV keeps recurring, you may want to consider other forms of birth control.


There are no specific preventive measures. The following general measures may help in preventing bacterial vaginosis or other vaginal disorders:

  • Using condoms with a new sexual partner. This can help to protect against other infections.
  • Keep the genital area clean.
  • Avoid vaginal douching.
  • Take showers rather than bathtubs if you are prone.
  • Wear cotton underpants.
  • Don’t sit around in wet clothing, such as a wet bathing suits.
  • After urination or bowel movements, cleanse by wiping or washing from front to back (vagina to anus).
  • Change tampons or pads frequently.
  • Avoid unnecessary use of antibiotics.

You should see your doctor immediately if you have:

  • New or/and unexplained symptoms develop.
  • Increasing abdominal pain, increasing vaginal discharge, or fever – this may suggest worsening infection.
  • Drugs used in treatment may produce side effects and you should discuss these with your doctor.

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