Is it thrush or bacterial vaginosis?

Thrush and bacterial vaginosis are common infections that can cause similar symptoms.

Here to provide an expert insight into thrush and bacterial vaginosis, including recurrent thrush, is Ms Pushpakala Maharajan, esteemed consultant obstetrician and gynaecologist.

What is the difference between thrush and bacterial vaginosis?

Thrush is an infection caused by the overgrowth of a yeast (a fungus), called Candida albicans, that is naturally found in the vagina, the mouth, and the gut. This type of fungus tends to overgrow after a change in the natural balance of microbes in the body, which happens if the immune system becomes weakened, for example.

Symptoms of thrush (in women) include:

• A thick, white vaginal discharge
• Itchiness and irritation around the vagina
• Soreness and pain when urinating or having sex

Bacterial vaginosis, on the other hand, is an infection caused by the overgrowth of a bacteria (the Gardnerella vaginalis bacteria, in most cases) that is naturally found in the vagina. This type of bacteria tends to overgrow after a change in the pH of the vagina disrupts the natural balance of bacteria.

Symptoms of bacterial vaginosis include:

• An unusual vaginal discharge
• A strong, unpleasant, fish-like vaginal odour
• A thin, watery, grey or white vaginal discharge

Some women with thrush or bacterial vaginosis may not get any symptoms at all.

Is it possible to have thrush and bacterial vaginosis at the same time?

When there is a predisposition, thrush and bacterial vaginosis can co-exist at the same time. This can occur, for example, if the vaginal pH changes in a woman with an autoimmune condition - the combination may trigger both infections.

Can untreated thrush lead to bacterial vaginosis?

Thrush and bacterial vaginosis are caused by different microbes in the body. Hence, one infection does not lead to the other.

When is a thrush infection considered recurrent?

A thrush infection is considered recurrent when a woman has had four or more episodes of thrush in a year.

What can cause recurrent thrush?

Some women may experience recurrent thrush infections if they receive inadequate treatment for the original thrush, or, if the original thrush does not respond to treatment.

As well as this, recurrent thrush infections can also develop if a woman:

• Has diabetes or high blood sugar levels
• Is taking antibiotics
• Is taking birth control pills
• Is having hormone replacement therapy
• Is pregnant
• Has an immunodeficiency disorder (for example, due to HIV)
• Suffers mechanical irritation in the vulvovaginal area

While thrush is not classified as a sexually transmitted infection (STI), some evidence suggests that (recurrent) thrush can also develop as a result of sexual activity.

How is recurrent thrush treated and managed?

There are two stages to treatment.

The first stage of treatment is known as ‘the induction course’. This generally involves a regimen of three doses of 150mg oral fluconazole (an oral antifungal) that need to be taken every 72 hours. The goal here is to treat the thrush infection present.

The second stage of treatment is known as ‘the maintenance course’. This generally involves 150mg oral fluconazole that needs to be taken once a week for six months. Having treated the thrush infection in the induction course, the goal here is to lower the amount of the Candida albicans fugus present.

If first-line treatment with oral fluconazole is not advisable or tolerated, alternative treatment regimens are available.

An alternative induction course generally involves topic imidazole therapy (for example, 500mg clotrimazole pessaries, which are intravaginal antifungal tablets) that need to be used for one or two weeks.

An alternative maintenance course generally involves 500mg clotrimazole pessaries that need to be used once a week for six months, or, 50-100mg oral itraconazole (another oral antifungal) that needs to be taken daily for six months.

Oral antifungal treatment is not recommended for women who are breastfeeding. Instead, clotrimazole pessaries should be used for both the induction and the maintenance courses of treatment.

A male sexual partner is not usually treated, unless they have diagnosed balanitis (inflammation of the head of the penis).

How successful is treatment for thrush?

Most cases of thrush will settle after treatment or after developing only one more episode of thrush.

Treatment can be repeated if a thrush infection becomes recurrent (four or more episodes in a year), with the maintenance course continued for longer (more than six months). While this has a success rate of 42 – 77 per cent, intake of probiotics during treatment can help improve outcomes.

Regardless of the treatment plan that is followed, women should seek medical attention if they:

• Have symptoms that do not improve or have symptoms that persist
• Develop a new thrush infection during the maintenance course of treatment
• Become pregnant
• Have side effects from the antifungal medication
• Start to breastfeed
• Develop new symptoms of thrush (for example, ulcers, blisters, abnormal vaginal bleeding, or a smelly or bloodstained vaginal discharge)
• Feel unwell

If you require expert treatment for thrush or bacterial vaginosis, do not hesitate to visit Ms Maharajan’s Top Doctors profile today.