Evaluation of direct microscopic examination, acridine orange staining and culture methods for the detection of Trichomonas vaginalis in vaginal discharge specimens

Abstract

Trichomonas vaginalis is the causative agent of human trichomoniasis which is a sexually transmitted disease mainly in women. The infection may be asymptomatic or symptomatic such as severe vaginitis and cervicitis. The aim of this study was to compare direct microscopic examination, acridine orange stained examination and culture in Modified Diamond medium, for the detection of T.vaginalis from the vaginal swab samples of 310 patients (age ranges: 17-45 years old) who were complaining from vaginal discharge. Of them 40 (12.9%) samples were found positive with culture, 20 (6.5%) were positive with direct microscopy and 19 (6.1%) were positive with acridine orange staining method. The positive results were obtained in 17 cases by each of the three methods, in 3 cases by direct microscopy and culture, in 2 cases by acridine orange staining and culture, and in 18 cases by culture only. T.vaginalis has been detected in 19.5% of 41 patients with itching, 15.7% of 190 patient with groin pain and 23.2% of 43 patients with cervical erosion, in addition to vaginal discharge, by at least one of the methods. In conditional evaluation, there were no statistically significant differences between T.vaginalis positivity with age groups and the contraceptive methods used. As a result, it was concluded that for the laboratory diagnosis of T.vaginalis, acridine orange staining technique does not have any superiority over direct microscopy. Although direct microscopy is a practical and economical method, it has low sensitivity, so all of the suspected samples which are found negative by this method, should be cultivated for a definite diagnosis.