The three most common causes of vaginal discharge are bacterial infections, or vaginosis; yeast infections, also known as candidiasis; and trichomoniasis. A vaginal discharge culture is used to diagnose the first two of these three conditions. Trichomoniasis is not detected by this test and must be tested separately.
The vaginal discharge culture is “positive” when yeast is present. In over 90% of cases, the yeast will be Candida albicans. Other types of yeast, such as Candida glabrata, or Saccharomyces cerevisiae, are grouped under the label “yeasts other than Candida albicans.” A culture is “negative” when there is no yeast growth (after 48 hours of culturing) and only normal vaginal flora composed of lactobacillus is observed. An “altered vaginal flora” means that lactobacilli are absent. The *** cultures indicate bacterial vaginosis, usually due to an overabundance of Gardnerella vaginalis. Other elements of the report (white blood cells, epithelial cells) help confirm the nature of the observations. When present, “clue cells” (vaginal cells lined with a large number of bacteria) confirm bacterial vaginosis.