Bacterial Vaginosis (BV), also known as vaginal bacteriosis is the most common cause of vaginal infection for women of childbearing age. Although it frequently develops after sexual intercourse with a new partner, bacterial vaginosis is not considered as an STI (sexually transmitted infection). BV is more common in women with multiple partners.

Bacterial vaginosis – not to be confused with candidiasis (yeast infection) or Trichomonas vaginalis (trichomoniasis) which are not caused by bacteria – is caused by an imbalance of naturally occurring bacterial flora (the usual bacteria found in a woman’s vagina). Smoking and the use of some hygiene products are linked to a higher risk of developing BV.

According to the National Health Service (NHS), UK, approximately 12% to 30% of adult women in the UK may be affected; about 20% of pregnant women in the UK are affected. The Centers for Disease Control and Prevention (CDC), USA, estimates that about 16% of US women are affected.

Bacterial vaginosis can sometimes be asymptomatic – about 50% of women with BV have no symptoms at all. Doctors say treatment is not required if the woman is found to have BV, but has no symptoms. Sometimes BV can appear and disappear for no reason.

Even though antibiotic medication is effective in up to 90% of cases, 25% of women will develop BV again within four weeks.

A pregnant woman with BV has a slightly higher risk of complications, such as giving birth before the 37th week of pregnancy.

Signs and symptoms of Bacterial Vaginosis

A symptom is something the patient senses and describes, while a sign is something other people, such as the doctor notice. For example, drowsiness may be a symptom while dilated pupils may be a sign.

Approximately 50% of all women with BV have no symptoms (asymptomatic). If a woman does have symptoms, she does not need to get tested to find out.

 The main sign is in the vaginal discharge:

Vaginal discharge may become watery and thin

Vaginal discharge may become grey or white

Vaginal discharge may have a strong and unpleasant smell, often described as fishy

The following symptoms are possible, but much less common:

Burning sensation during urination

Itching around the outside of the vagina

 Causes of bacterial vaginosis

 We know that bacterial vaginosis is linked to an imbalance in the bacteria that are normally found in a female’s vagina – an imbalance in the vagina’s naturally occurring bacterial flora. However, nobody fully understands why this imbalance occurs. The vagina usually contains mostly good bacteria and few harmful bacteria – bacterial vaginosis occurs when these harmful bacteria grow in numbers. We do not know what role these harmful bacteria play in causing BV.