Accuracy of detection of trichomonas vaginalis organisms on a liquid-based papanicolaou smear

Am J Obstet Gynecol. 2003 Feb;188(2):354-6. doi: 10.1067/mob.2003.8.


Objective: The study was undertaken to determine the accuracy of the liquid-based Papanicolaou (Pap) smear in the detection of Trichomonas vaginalis organisms in women.

Study design: Two hundred three consecutive patients who had the liquid-based Pap smear also underwent a culture for T vaginalis. A wet mount was performed if symptomatic. Results were analyzed for sensitivity, specificity, and positive and negative predictive values.

Results: Forty-four patients (21.6%) had a positive culture. On the liquid-based Pap smear, 28 patients (13.8%) were positive for T vaginalis, showing a sensitivity of 61.4%, a specificity of 99.4%, a positive predictive value of 96.4%, and a negative predictive value of 90.8%. When wet mount and culture were compared, a sensitivity of 50%, a specificity of 93%, a positive predictive value of 77%, and a negative predictive value of 80% were obtained.

Conclusion: The presence of T vaginalis organisms, as stated by the liquid-based Pap smear pathology report, is accurate and warrants treatment without further testing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Animals
  • Female
  • Humans
  • Middle Aged
  • Papanicolaou Test*
  • Predictive Value of Tests
  • Sensitivity and Specificity
  • Trichomonas vaginalis / isolation & purification*
  • Vaginal Smears / methods*
  • Vaginal Smears / standards