Detection of Chlamydia trachomatis and Trichomonas vaginalis by polymerase chain reaction in introital specimens from pregnant women

OBJECTIVE: We analyzed whether specimens obtained from the vaginal introitus were comparable to endocervical and posterior vaginal vault specimens for detection of Chlamydia trachomatis and Trichomonas vaginalis by polymerase chain reaction. STUDY DESIGN: Introital and endocervical specimens were obtained from 300 women at the first prenatal visit. Specimens from the posterior vaginal vault were also obtained from 219 of these patients. All samples were tested for C. trachomatis and T. vaginalis by polymerase chain reaction. RESULTS: C. trachomatis was identified in the endocervices of 36 women (12.0%); all but one of these women and none of the endocervical-negative women were positive for this organism in the introitus. T. vaginalis was detected in 22 women (10.0%); all but one were also introitus positive for this organism. Compared with endocervical and vaginal polymerase chain reaction, introital testing had a 100% specificity and a 97.2% and 95.5% sensitivity for detecting C. trachomatis and T. vaginalis, respectively. CONCLUSION: Polymerase chain reaction analysis of vaginal introital specimens is highly sensitive and specific in detecting C. trachomatis and T. vaginalis in pregnant women and thus provides an alternative to speculum examination in screening for these pathogens.