Understanding bacterial vaginosis: an expert’s guide

The most frequent cause of discharge in women of child-bearing age is bacterial vaginosis (BV). Distinguished consultant in sexual and reproductive health Dr Emily Lord examines bacterial vaginosis, including the causes, symptoms and treatment options.

What causes bacterial vaginosis?

The vagina naturally contains a balance of bacteria. In a healthy vagina, lactobacilli dominate and play a crucial role in maintain an acidic environment (pH <4.5) which prevents the growth of unhealthy bacteria. 

BV develops when the vaginal pH goes above 4.5 and up to 6.0.  In this environment, anaerobic bacteria can flourish. The most common types are Gardnerella vaginalis, Prevotella species and Mycoplasma Hominis.

Whilst the cause is not fully understood, risk factors for infection include:

• Douching (washing inside of the vagina).
• Sexual activity, including receptive cunnilingus (oral sex), recent change in sexual partner, multiple sexual partners, and lack of condom use.
• Women who have sex with women.
• Ethnicity: black women are more likely to develop BV than non-black women.
• The presence of a concurrent STI, e.g. chlamydia.
• BV prevalence increase during /after menstruation.
• Smoking.

Symptoms of bacterial vaginosis

Bacterial vaginosis may present with a range of symptoms, although up to 50% have no symptoms at all.

Symptoms may include:

• A thin, watery discharge, with a fishy odour, which is particularly noticeable after sexual intercourse.
• Although not usually linked to local irritation or soreness, some symptoms may arise due to frequent washing or use of sanitary products.

Diagnosis

Diagnosing bacterial vaginosis typically involves a genital examination and pH assessment. Samples may be taken for direct microscopy – whereby the sample is gram stained, and assessed under the microscope using either the Hay/Ison criteria – which essentially looks at the number of lactobacilli, the presence of anaerobic bacteria.

It is also important to rule out other STIs, including chlamydia, gonorrhoea and trichomonas.

Treatment

Treatment is only recommended for women who have symptoms.

General advice

• Avoid douching.
• Do not use perfumed soaps or ‘special vaginal washes’.
• Stick to washing with water and a soap substitute/emollient only.

Antibiotics

Treatment for BV usually involves antibiotics, such as metronidazole or clindamycin, which can be administered orally or topically as vaginal gels or creams. It is important to finish the full course of antibiotics, even if symptoms improve.

Women who are pregnant should seek specialised advice as soon as possible.

Recurrent BV

Whilst there is no current definition of what constitutes ‘recurrent BV’, it is certainly something that women frequently seek help for, describing either partial response to antibiotics, or full response and then reoccurrence of symptoms within days or weeks. There is debate as to the ideal treatment options, and whether treating sexual partners may help.

Prophylactic antibiotics

Some women will manage treating recurrent episodes with oral antibiotics, if recurrences are particularly frequent, some may benefit from prophylactic antibiotics, e.g. using topical metronidazole twice a week.

Probiotics

There is some evidence that probiotics may help reduce the frequency of recurrences.

Lactic acid treatments

Whilst there is a paucity of trial-based evidence to support the use of lactic acid products, some women find them helpful to use after antibiotic treatment to reduce the frequency of recurrences. 

Newer therapies

Newer therapies, are being used by specialists and are worth discussing with specialist in the field.

While not usually considered a serious health threat, bacterial vaginosis can cause significant worry for women. Understanding the causes, symptoms, and treatment options for BV is crucial for promoting vaginal health and overall well-being. If you suspect you may have BV or experience persistent vaginal symptoms, consult a specialist for proper diagnosis and treatment.

If you would like to book a consultation with Dr Lord, do not hesitate to do so by visiting his Top Doctors profile today