Accuracy of the clinical diagnosis of vaginitis compared with a DNA probe laboratory standard

Obstet Gynecol. 2009 Jan;113(1):89-95. doi: 10.1097/AOG.0b013e3181909f63.


Objective: To estimate the accuracy of the clinical diagnosis of the three most common causes of acute vulvovaginal symptoms (bacterial vaginosis, candidiasis vaginitis, and trichomoniasis vaginalis) using a traditional, standardized clinical diagnostic protocol compared with a DNA probe laboratory standard.

Methods: This prospective clinical comparative study had a sample of 535 active-duty United States military women presenting with vulvovaginal symptoms. Clinical diagnoses were made by research staff using a standardized protocol of history, physical examination including pelvic examination, determination of vaginal pH, vaginal fluid amines test, and wet-prep microscopy. Vaginal fluid samples were obtained for DNA analysis. The research clinicians were blinded to the DNA results.

Results: The participants described a presenting symptom of abnormal discharge (50%), itching/irritation (33%), malodor (10%), burning (4%), or others such as vulvar pain and vaginal discomfort. According to laboratory standard, there were 225 cases (42%) of bacterial vaginosis, 76 cases (14%) of candidiasis vaginitis, 8 cases (1.5%) of trichomoniasis vaginalis, 87 cases of mixed infections (16%), and 139 negative cases (26%). For each single infection, the clinical diagnosis had a sensitivity and specificity of 80.8% and 70.0% for bacterial vaginosis, 83.8% and 84.8% for candidiasis vaginitis, and 84.6% and 99.6% for trichomoniasis vaginalis when compared with the DNA probe standard.

Conclusion: Compared with a DNA probe standard, clinical diagnosis is 81-85% sensitive and 70-99% specific for bacterial vaginosis, Candida vaginitis, and trichomoniasis. Even under research conditions that provided clinicians with sufficient time and materials to conduct a thorough and standardized clinical evaluation, the diagnosis and, therefore, subsequent treatment of these common vaginal problems remains difficult.

Level of evidence: II.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Animals
  • Candida / classification
  • Candidiasis, Vulvovaginal / diagnosis*
  • Candidiasis, Vulvovaginal / microbiology
  • DNA Probes*
  • Female
  • Gardnerella vaginalis / classification
  • Humans
  • Middle Aged
  • Military Personnel
  • Predictive Value of Tests
  • Sensitivity and Specificity
  • Trichomonas Vaginitis / diagnosis*
  • Trichomonas Vaginitis / microbiology
  • Trichomonas vaginalis / classification
  • Vaginosis, Bacterial / diagnosis*
  • Vaginosis, Bacterial / microbiology
  • Young Adult


  • DNA Probes