Some infections are associated with more serious diseases. The most common vaginal infections are bacterial vaginosis, trichomoniasis, and vaginal yeast infection or candidiasis. Some vaginal infections are transmitted through sexual contact, but others such as yeast infections probably are not, depending on the cause. Vaginal Yeast Infection Vaginal yeast infection or vulvovaginal candidiasis is a common cause of vaginal irritation. Doctors estimate that approximately 75 percent of all women will experience at least one symptomatic yeast infection during their lifetimes.
Yeast are always present in the vagina in small numbers, and symptoms only appear with overgrowth.
Several factors are associated with increased symptomatic infection in women, including pregnancy, uncontrolled diabetes mellitus, and the use of oral contraceptives or antibiotics. Other factors that may increase the incidence of yeast infection include using douches, perfumed feminine hygiene sprays, and topical antimicrobial agents, and wearing tight, poorly ventilated clothing and underwear. Whether or not yeast can be transmitted sexually is unknown. Because almost all women have the organism in the vagina, it has been difficult for researchers to study this aspect of the natural history. The most frequent symptoms of yeast infection in women are itching, burning, and irritation of the vagina.