What is Vaginal Thrush infection?
Candida is one of the potential pathogens that live with humans more or less all the times, but rarely cause disease, as they are usually kept in check by the immune system, or in the case of VVC by the friendly bacteria that live in the vagina that belong to the family of lactobacilli. These bacteria are similar to those that ferment milk into yoghurt and the keep the pH of the vagina low, which creates and environment that is unfriendly to the Candida yeast.
Disruptions in this bacterial flora, either by external factors like e.g. douching, use of antibiotics, or internal factors like hormonal changes can create space and/or an environment that is favorable for the growth of Candida. This leads to an overgrowth of the vagina with the Candida yeast, which can cause irritation, burning, itching, vaginal soreness, pain during sexual intercourse, external pain when urinating and a thick white discharge.
How common is Vaginal Thrush infection and what are the risk factors?
Candida lives commonly in many people on the body or in body cavities like the genitals, and the mouth. It does not always cause disease, as its growth it usually kept in check by the cooperation of the immune system and friendly bacteria that also live in these places and that create an environment in which the yeast can grow only very badly. A study with women in New Zealand showed that 19% of apparently healthy and symptom-free women had Candida yeast in their vagina. It is estimated that about 75% of women will have at least on episode of symptomatic Vulvovaginal Candidiasis during their life time. 40-45% of women have more than one symptomatic episode during their life time.
Risk factors and prevention of Vaginal Thrush infection
There are many factors that increase the risk to develop vaginal thrush infection. Prevention aims at decreasing the risk by modifying or avoiding these risk factors.
The immune system plays a very important role in keeping Candida that has settled on our body in check. Immunosuppression of any kind is therefore a risk factor for developing vaginal thrush infections. The immune system can be suppressed because of certain medications like corticosteroids, or other immunosuppressants that are given for a variety of medical conditions like e.g. autoimmune diseases, asthma, and organ transplantations.
Certain cancer drug can suppress the immune system. HIV infection is a risk factor not only for the development of vaginal thrush infections, but also for the infection leading to sometimes serious complications. These risk factors cannot easily be modified, but in the case of a Vaginal Thrush infection, the treating doctor should know about them, as they might make treatments for Vaginal Thrush Infections less effective.
The other most common risk factors have to do with the bacteria that live in the vagina. These lactobacilli form an environment that is acidic, i.e. has a low pH (<4.5) and that is unfavorable for the growth of Candida. Anything that can disturb these bacteria is a risk factor for the development of Vaginal Thrush infections. The bacteria can be killed by the use of antibiotics, either as pills or as injections, as they will kill bacteria indifferently all over the body. Douching and the use of perfumed feminine hygiene products also can kill these bacteria and their use is associated with a higher incidence of Vaginal Thrush infections. The bacteria can also be disturbed by hormonal change like in pregnancy, menopause, or hormone replacement therapy.
Sugar in the vagina and urine like it is common in uncontrolled diabetes enable the yeast to grow faster, as it will use the sugar as fuel. Uncontrolled diabetes is therefore another risk factor for Vaginal Thrush infections. Heat and moisture trapping tight clothes are another risk factor.
To help prevent Vaginal Thrush infections, loose clothes should be worn. A well balanced diet that contains yoghurt with live culture has been shown to reduce the incidence. The treatment of diabetes to control blood sugar and of any conditions that weaken the immune system can also help prevent the disease. Douching and perfumed feminine hygiene product should be avoided.
How to get rid of Vaginal Thrush infection?
Once the infection is established these measures will not help anymore. The doctor can prescribe a wide variety of topical antifungal medications. Topical medications come as cream or gel and are directly applied to the vagina. There are also non-prescription topical treatments available, as well as home remedies for yeast infection
The most frequently used topical antifungal drugs are clotrimazole, nystatin, ketoconazole. Nystatin is normally not used as a cream or gel, but as a vaginal tablet that lasts for two weeks. There are also treatment options available that require taking pills. A single 150mg tablet of fluconazole has been shown to cure Vaginal Thrush infections in 90% of all cases.
If patients have a severe infection that requires hospitalization like it can occur in severely immuno-suppressed patients different drug will be used. In these cases the most regularly used drugs are amphotericin B, caspofungin, and voriconazole.
Since Candida can develop resistance to anti-fungal drugs, it is possible that recurrent infections cannot be successfully treated with a drug that used to work in an earlier infection. Recurrent VVC, which is defined as more than three episodes during the course of a year and affects less than 5 % of women, is generally also treated with topical antifungal drugs, but the treatment course might be prolonged. Some patients will receive a weekly oral dose of fluconazole to keep the infection from reoccurring. This maintenance therapy is an effective therapy for the prevention of recurrent VVC. However, many women who have recurrent VVC, with some estimates as high as 30-50%, will relapse after the maintenance therapy is stopped.