Candidiasis (kan-duh-DIE-uh-sus), also commonly referred to as a yeast infection, is primarily caused by a yeastlike fungus called Candida albicans.

Incidence and Transmission

Candidiasis is the second most common vaginal infection in North America. An esti­mated 75% of women will have at least one genital candidiasis infection in their lifetime (Workowski et al., 2010). The microscopic Candida albicans organism is normally present in the vagina of many women; it also inhabits the mouth and large intestine of a large number of women and men. A disease state results only when certain conditions allow the yeast to overgrow in the vagina. This accelerated growth can result from pregnancy, use of oral contraceptives, or diabetes—conditions that increase the amount of sugar stored in vaginal cells (Candida albicans thrives in the presence of sugar) (Centers for Disease Con­trol, 2009j). Another factor is the use of oral antibiotics or spermicidal jellies or creams,

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which reduce the number of lactobacilli (mentioned earlier as important for a healthy vagi­nal environment). This reduction permits Candida albicans to multiply rapidly.

If the yeast organism is not already present in the woman’s vagina, it can be transmit­ted to this area in a variety of ways. It can be conveyed from the anus by wiping back to front or on the surface of a menstrual pad, or it can be transmitted through sexual inter­action, because the organism can be harbored in various reservoirs in the male body, espe­cially under the foreskin of an uncircumcised man (Ringdahl, 2000). The organism can also be passed from a partner’s mouth to a woman’s vagina during oral sex (Greer, 1998).