Bacterial vaginosis

Bacterial vaginosis, or BV, happens when the natural balance of bacteria in the vagina changes. The healthy bacteria that usually protect the vagina reduce, and other bacteria increase. This can lead to symptoms such as unusual discharge or a fishy odour. BV is the most common cause of abnormal vaginal discharge in people of childbearing age. Up to half of people with BV may have no symptoms.

BV is not usually classed as a sexually transmitted infection, but sex can play a role in triggering it or in it coming back. BV can happen with or without sexual activity. It is more common after a change in sexual partner, and it may also come back after treatment. Research suggests that BV-associated bacteria may sometimes be shared between sexual partners, particularly between partners who both have vaginas. BV may also be linked to vaginal douching (cleaning inside the vagina with water, soap or other products), and sex toys or fingers may sometimes play a role in moving bacteria into the vagina. It isn't always clear why some people get BV and others don't.

The following practices can increase your risk of getting bacterial vaginosis:

• Sex with a new partner is associated with getting bacterial vaginosis
• Sex with an ongoing partner after treatment and not using condoms, is associated with getting bacterial vaginosis back again
• Having a sexual partner with a vagina
• Not using condoms correctly every time you have sex from start to finish
• Cleaning inside the vagina with water, soap or other products (douching)
• Cigarette smoking
• Having an intrauterine contraceptive device may increase the risk although the association is not entirely clear.

Bacterial vaginosis may cause an increase in vaginal discharge (fluid leaking from the vagina).  This discharge is often thin, watery, white or grey, and there may be a strong sour or fishy smell which may worsen after sex. About 50% of people with BV have no symptoms at all. BV does not usually cause itching, burning, or soreness. If you have those symptoms, it may be another condition such as thrush, or sometimes an STI. Other infections can also cause discharge, so it is important to get checked if you are unsure.

Bacterial vaginosis is easy to treat and is not likely to lead to any serious health problems. If you have no symptoms at all then there is no need to treat the infection and often the body will naturally correct the imbalance.

If you are experiencing symptoms then bacterial vaginosis can be easily diagnosed by doing a vaginal swab test at your local sexual health clinic. If you are not noticing symptoms then testing and treatment is not required as the body will naturally balance itself. Male partners do not require testing, however if the bacterial vaginosis is recurring they may be advised to have treatment.

Treatment of bacterial vaginosis is generally not required if there are no symptoms. A common treatment is metronidazole tablets taken twice a day for 7 days. An alternative antibiotic may be used if metronidazole is not suitable. Metronidazole can sometimes cause nausea or an upset stomach, and taking it with food may help. Do not drink alcohol while taking metronidazole and for at least 48 hours after finishing it, as this can make you feel very unwell.

BV can come back after treatment, and recurrence is common. If it keeps returning, talk with your doctor or nurse, as there may be other treatment options or further advice depending on your symptoms and how often it is happening. Specialist advice is recommended if BV keeps coming back, especially if there are more than 3 recurrences in 12 months.

Male partners do not require testing, however if the bacterial vaginosis is recurring they may be advised to have treatment.

It is not always clear why some people get BV and others don't - these measures may help to prevent bacterial vaginosis.

• ‍Condoms used correctly every time you have sex from start to finish will provide some protection from bacterial vaginosis and offer good protection from many other sexually transmitted infections
• Avoid douching or bathing with bubble baths or other non-pH balanced detergents. Avoid using soap, vaginal wipes or antiseptics
• Wear cotton underwear
• If you use sex toys, clean them well and avoid sharing them unless they are covered with a new condom each time.

If you are diagnosed with bacterial vaginosis, partner notification is not required as this is not considered a sexually transmitted infection. If you are experiencing recurrent bacterial vaginosis infections there is increasing evidence that treating your sexual partner/s may reduce recurrences - speak with your health professional about this.