General Obstetrics and Gynecology Gynecology
Accuracy of detection of trichomonas vaginalis organisms on a liquid-based papanicolaou smear,☆☆

https://doi.org/10.1067/mob.2003.8Get rights and content

Abstract

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. (Am J Obstet Gynecol 2003;188:354-6.)

Section snippets

Material and Methods

From June 2001 to October 2001, after the protocol was approved by the Institutional Review Board of University Hospitals of Cleveland, 203 consecutive patients seen in an urban women's health center who required a Pap smear also had a culture taken for T vaginalis using the In Pouch TV (Biomed Diagnostics). After giving consent, patients first had a Pap smear with the standard liquid-based method used in our center, followed by a cervicovaginal swab for T vaginalis. If the patient was

Results

Demographic data are shown in Table I.

. Demographics (n = 203)

Race
White8 (4%)
African American195 (96%)
Pregnant55 (27%)
Gravidity*2 (0-10)
Parity*1 (0-8)
Age22 (18-67)
Gestational age*11 (6-34)†
Presence of symptoms85 (42%)
Previous STDs by history124 (61%)
*Median (range). †In weeks.
In this population, 56 (27%) were pregnant at the time of the study, 85 (42%) reported a vaginal discharge, 124 (61%) had a history of previous STDs with T vaginalis (51%) and Chlamydia trachomatis equally prevalent (51%).

Comment

Although the presence of T vaginalis on conventional Pap smear is still reported as an incidental finding by the pathologist giving it low sensitivity, the high specificity of the test improves the diagnosis of this disease in patients who otherwise were asymptomatic and did not have a wet mount at their office visit. In asymptomatic patients, the liquid-based Pap smear was able to detect the presence of the organism in 9.6% more patients who otherwise would not have had a test performed.

References (13)

  • LR DeMeo et al.

    Evaluation of a deoxyribomucleic acid probe for the detection of Trichomonas vaginalis in vaginal secretions

    Am J Obstet Gynecol

    (1996)
  • MR Spence et al.

    The clinical and laboratory diagnosis of Trichomonas vaginalis infection

    Sex Transm Dis

    (1980)
  • GP Schmid et al.

    Evaluation of six media for the growth of Trichomonas vaginalis from vaginal secretions

    J Clin Microbiol

    (1989)
  • GD Eltabbakh et al.

    Value of wet mount and cervical cultures at the time of cervical cytology in asymptomatic women

    Obstet Gynecol

    (1995)
  • JN Krieger et al.

    Diagnosis of trichomoniasis: comparison of conventional wet mount examination with cytologic studies, cultures and monoclonal antibody staining of direct specimens

    JAMA

    (1988)
  • CS Petersen et al.

    Ignored trichomonal infestation diagnosed by Papanicolaou smear

    Genitourin Med

    (1995)
There are more references available in the full text version of this article.

Cited by (60)

  • Prevalence and spatial heterogeneity of Trichomonas vaginalis infection among the female population and association with climate in Guangxi Zhuang autonomous region, Southern China

    2022, Acta Tropica
    Citation Excerpt :

    Hence, asymptomatic TVI cases are likely to be found in this study. Liquid-based cytology features satisfactory sensitivity and specificity in the diagnosis of TV (Lara-Torre and Pinkerton, 2003). In the present study, the infection rate was lower than those in previous studies in China (Luo et al., 2016; Su et al., 2016), which may be related to the inexperience in identifying T. vaginalis through liquid-based cytology.

  • Risk of high-risk human papillomavirus infection and cervical precancerous lesions with past or current trichomonas infection: a pooled analysis of 25,054 women in rural China

    2018, Journal of Clinical Virology
    Citation Excerpt :

    Previous studies that evaluated the association between TV infection on HPV persistence and CIN+ had inconsistent results. Several studies reported no causal role for TV on cervical cancer [36,37]. A frequently cited meta-analysis of 24 studies showed an increased relative risk for cervical cancer with TV infection; [13] however, this analysis was powered by only two cohort studies (Gram 1992; Zhang 1991).

  • Testing and treatment for sexually transmitted infections in adolescents-what's new?

    2014, Journal of Pediatric and Adolescent Gynecology
    Citation Excerpt :

    Wet mount is currently the most commonly used testing methodology for Trichomonas vaginalis (TV) but suffers from poor sensitivity (60%-70%).40–42 PAP smear has been found to have a sensitivity similar to wet mount at 60%, which is improved when liquid media are used.43 TV testing methodologies clinically available are culture, POCTs, and NAAT tests (Amplicor PCR and APTIMA-Gen-Probe).

  • Trichomoniasis: The "neglected" sexually transmitted disease

    2013, Infectious Disease Clinics of North America
    Citation Excerpt :

    Cultures may be inoculated with a variety of specimen types from men or women, including genital secretions, semen, or urine. Neither traditional nor liquid-based Papanicolaou tests (Pap smears) are considered appropriate diagnostic or screening tests for trichomoniasis because of their poor sensitivity.20,21 However, the specificity of liquid-based cytology for T vaginalis is high.22,23

  • Urethritis, Vulvovaginitis, and Cervicitis

    2012, Principles and Practice of Pediatric Infectious Diseases, Fourth Edition
View all citing articles on Scopus

Supported by departmental funds.

☆☆

Reprint requests: Eduardo Lara-Torre, MD, Department of Obstetrics and Gynecology, University of Louisville, 550 S Jackson St, Louisville, KY 40202. E-mail: [email protected]

View full text