Diagnosis of Trichomonas vaginalis in female children and adolescents evaluated for possible sexual abuse: a comparison of the InPouch TV culture method and wet mount microscopy.

STUDY OBJECTIVE: To compare the performance of wet mount microscopy and the InPouch TV culture method in diagnosing Trichomonas vaginalis in a cohort of female children and adolescents evaluated for possible sexual abuse.

DESIGN: A prospective study in which samples for both wet mount and InPouch TV were collected from the vaginal vault of each participant. The wet mount was examined microscopically for the presence of motile trichomonads, and the InPouch TV was analyzed in accordance with manufacturer specifications.

SETTING: A regional, university-affiliated sexual abuse center in Nashville, TN.

PARTICIPANTS: Females (N = 271) aged 10 to 17 years (inclusive) who met screening criteria for sexually transmitted infection testing in accordance with Centers for Disease Control recommendations, and who exhibited evidence of at least partial hymenal estrogenization.

MAIN OUTCOME MEASURES: A Trichomonas vaginalis diagnosis either via detection of motile trichomonads on wet mount or a positive InPouch TV.

RESULTS: The median age of the 271 participants was 13.6 years, 88% (235/268) were genital Tanner stage 4 or 5, and 66% (173/263) were Caucasian. Trichomonas vaginalis was diagnosed by either wet mount or InPouch TV in 4% (12/274) of the possible sexually transmitted infection exposures. The sensitivity of wet mount was 8/12 = 0.67 (95% confidence interval [CI]: 0.39, 0.86) and specificity was 262/262 = 1.00 (95% CI: 0.99, 1.00). The false negative rate of wet mount was 4/12 = 0.33 (95% CI: 0.14, 0.61).

CONCLUSIONS: A culture-based method such as InPouch TV should be considered for Trichomonas vaginalis diagnosis when evaluating children and adolescents in whom sexual abuse is a concern.