Candida normally lives harmlessly in the body, but under certain conditions it may multiply out of control. Candida can affect different parts of the body, causing either localised infections or overwhelming illness, depending on the individual’s general state of health. Yeast infection of the vaginal area is common. If the infection is also present at the vulva (the area around the entrance to the vagina), the condition is known as vulvovaginal candidiasis. The infection commonly occurs as a result of self-contamination with yeast organisms from the rectal passage.
Sexual transmission is possible but unusual. Vaginal candida infections are not usually transmitted sexually. They are often listed among sexually transmitted infections only because they may occur with other types of reproductive system infections.
WHAT CAUSES VAGINAL CANDIDIASIS?
Candidiasis, also known as ‘Candida’ or ‘yeast’, is an infection caused by strains of Candida fungi, especially Candida albicans. Candida fungi usually live harmlessly along with the ‘friendly’ species of bacteria that normally colonise the mouth and gastrointestinal and urogenital tracts.
In a healthy person, the growth of candida is kept in check by a properly functioning immune system and the presence of friendly bacteria.
However, certain internal and external factors can change the normal environment and trigger an overgrowth of the yeast. Candida fungi can multiply out of control if the numbers of friendly bacteria are reduced, the immune system is weakened, or other conditions for yeast proliferation occur.
When fungal growth at a certain body site exceeds the body’s ability to control it, yeast infection develops.
WHAT ARE THE RISK FACTORS FOR CANDIDIASIS?
The following are factors that can predispose one to candida overgrowth:
- Antibiotics can reduce the number of friendly intestinal bacteria which normally help to keep candida under control.
- Medications such as steroid hormones, immunosuppressant, and anti-inflammatory drugs, chemotherapy drugs, and ulcer medications or acid blockers used for prolonged periods.
- Immune deficiency. Diseases such as Aids and cancer can weaken the immune system. The immune system can also become weaker in the elderly.
- Diabetics are prone to yeast infections, especially when their blood sugar levels are not well controlled. High levels of sugar in the blood and urine, and a low resistance to infection are conditions that encourage yeast growth.
- Certain genetic disorders, such as coeliac disease (which involves intestinal malabsorption) or haemochromatosis (in which iron accumulates in body tissue).
- Hormonal imbalance, as a result of menstruation, pregnancy, diabetes, birth control pills (usually in the first three months of taking them), or thyroid disease.
- Women tend to be more susceptible to vaginal yeast infections if they are under stress, have an inadequate diet, lack sleep, or are ill. Although it is not classified as a sexually transmitted infection, yeast infections are common among younger women (ages 20-40), especially after becoming sexually active. During their lifetimes, about 75% of all women are likely to have at least one vaginal candida infection before they reach menopause, and up to 45% will have two or more.
- When the balance between commensal (friendly) and pathogenic (disease-causing) bacteria in the normal intestinal flora is disturbed, for example due to excessive alcohol consumption and certain chemicals.
- A moist, warm environment. Yeast infections often develop where a moist, warm environment encourages fungal growth. Prime areas include the webs of fingers and toes, nails, genitals, and folds of skin. This is particularly the case in diabetics.
- Tight clothing, especially underwear, that promotes moisture build-up.
- Being obese (more than 20% overweight).
- People whose work requires that they spend long periods of time with their hands in water, or who wear rubber gloves, are predisposed to cutaneous candidiasis.
- In rare cases, the candida fungus may invade the body at certain sites: intravenous (IV) tube, urinary catheter, tracheostomy, ventilation tubing, or surgical wounds. If the infection spreads through the bloodstream to the kidneys, lungs, brain, or other organs, it can cause serious systemic complications. These develop only in people who are seriously ill or who have other health problems that weaken the immune system.
Other things to bear in mind:
- If a woman has a vaginal yeast infection when she gives birth, the baby may get yeast (thrush) in its throat or digestive tract.
- Thrush is a common minor infection in babies and young children.