Obstetrics & Gynecology
Trichomonas vaginales is the organism observed on the wet
preparation. Over 3 million women are diagnosed with trichomoniasis yearly.
Infection occurs in the vagina, urethra, and bladder. The organism is
usually transmitted by sexual intercourse; however, T. vaginalis has been
known to survive outside the body for several hours and, rarely, may be
transmitted by fomites such as clothing or towels. Between 20% and 50% of
patients with trichomoniasis are asymptomatic when the flagellated
protozoa are found on microscopic examination of a wet preparation
obtained during a Papanicolaou test. When tested, the vaginal pH level is
usually greater than 4.5 when this organism is present. A pH less than
4.5 usually rules out bacterial vaginosis and trichomoniasis, and a pH
greater than 4.5 usually signifies an unhealthy vaginal ecosystem.
Candidiasis usually occurs in patients with a vaginal pH of less than 4.5.
A healthy vaginal pH usually ranges from 3.8 to 4.3. The hallmark of the
wet preparation for bacterial vaginosis is the "clue cell" of the bacteria
adherent to the squames. The pseudohyphae of yeast are the hallmark of the
wet preparation for candidiasis, better visualized by a potassium hydroxide
- > 4.5.
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