health

The fungus that causes most vaginal yeast infection is usually Candida
albicans (KAN-di-da AL-bi-kanz). It is naturally present in the vagina (va-
JY-na), the gastrointestinal* tract, and the mouth. It is part of the vaginal
and gastrointestinal flora. In the vagina and in the gastrointestinal tract,
the Candida organisms usually remains in balance with various bacteria
that are also found in these naturally moist areas (meaning that the presence
of bacteria and other components of the flora helps to keep Candida
growth in check). All of these microorganisms are competitors for the same
resources, and a reduction in the level of one becomes an opportunity for
another to flourish. When this ecological balance is disrupted, Candida
growth may become Candida overgrowth (candidiasis). Vaginal candidiasis
will develop quickly when this excessive growth occurs in the vaginal
area. (When Candida infection involves the mouth, it is called thrush.
When it involves babies’ diaper area, it is called candidal diaper rash.)
Candida fungus cells can multiply too much when a person is taking
an antibiotic, which may destroy too many of the bacteria that usually
keep the fungus in check. Other situations that may cause the fungus
to grow out of control are the use of birth control pills, pregnancy, and
the use of drugs that suppress the immune system. When a woman
becomes immunocompromised (has an immunodeficiency disease such
as AIDS, or is taking an immunosuppressant medication—for example,
in preparation for organ transplantation) she will also be more likely to
develop a vaginal yeast infection. Sugar causes yeasts to multiply. Women
with diabetes have higher blood sugar levels, and their vaginal secretions
contain more glucose. Thus, a woman with diabetes is more likely to
develop a vaginal yeast infection.
Estimates indicate that about 75 percent of women have a yeast infection
at least once in their lifetime. Half of them have the infection more
than once.