National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention
Division of Sexually Transmitted Diseases
Program and Training Branch
Pathogenesis and Microbiology
Candida species are normal flora of the skin and the vagina and are not considered to be sexually transmitted pathogens. Yeast grows as oval budding cells and as chains of cells (pseudohyphae). Candida species may be isolated from the lower genital tract in approximately 20% of asymptomatic healthy women without abnormal discharge.
Symptomatic candidiasis is caused by an overgrowth of Candida albicans
and Candida species. It is thought that changes in the host vaginal environment are usually necessary before the organism induces pathologic effects.
Disruption of normal vaginal ecology and host immunity can occur with diabetes, pregnancy, or HIV disease. In some women, disruption can occur with the use of antibiotics and douching.