Vaginal Health

Updated 29 October 2014

Bacterial vaginosis

Bacterial vaginosis is the most common of vaginal infections. Here's everything you need to know.


Bacterial vaginosis (BV) is also sometimes called anaerobic vaginal discharge, non-specific vaginal discharge or Gardnerella vaginal discharge. BV is one of the most common vaginal infections.


Although the exact causes of BV are unknown, it is caused when the delicate eco-system of the vagina is upset because of the rapid growth of several kinds of bacteria that normally live in the vagina.

Small organisms called Lactobacilli help to keep the pH at the right level, but using antibiotics, soaps and even having sex can leave the vagina more alkaline, thereby encouraging bacterial growth.

BV may also be associated with douching and smoking. Anecdotally, there appears to be a link between BV and times of stress in a woman’s life


While some women with BV may be asymptomatic or don’t have any symptoms, others may present with some distinguishing symptoms such as a thin, off-white, grey vaginal discharge accompanied by a "fishy" or "musty" odour which gets stronger during menstruation, after sex and after washing with soap.

The redness and itching that is associated with yeast or thrush infections tends to be absent with BV.


BV can be treated with over the counter topical (vaginal) or oral antibiotics such as metronidazoleor clindamycin. On occasion however, it may require long-term or repeat treatments.

Many doctors believe metronidazole shouldn't be used during the first three months of pregnancy as its safety has not been established.

During the treatment cycle, it is recommended that you refrain from having sex. In general, it is not necessary to treat male sex partners. BV may occur between women who have sex with other women, in which case both partners need to be treated.


For many women, BV is a nuisance, but for others it can have a serious effect on their reproductive health.

If left untreated, BV can lead to abnormal pap smears, further infection and adverse pregnancy outcomes, such as miscarriage, preterm labour and birth as well as postbirth intrauterine infection.

It could also significantly increase a woman’s chance of HIV infection by up to four times and make her more susceptible to other Sexually Transmitted Infections (STIs) such as trichomoniasisand chlamydial cervicitis.


Recurrence of BV is very common and has been reported to be as high as 70% over a period of nine months following initial diagnosis. In this situation, long-term treatment over 6 months using a vaginal preparation has been reported to be effective.

Read more:

How much do you know about STI's? Do the quiz 
What could be the cause of a bad smelling vagina?
Everything you need to know about thrush

Image: Per Grinsted / Medicinsk Webdesign, via Wikimedia Commons

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