Improved diagnosis of Trichomonas vaginalis infection by PCR using vaginalswabs and urine specimens compared to diagnosis by wet mount microscopy, culture, and fluorescent staining

Four vaginal cotton swab specimens were obtained from each of 804 women vis iting the outpatient sexually transmitted disease clinic of the Erasmus Uni versity Medical Center Rotterdam, Rotterdam, The Netherlands, for validatio n of various forms of Trichomonas vaginalis diagnostic procedures. One swab specimen was immediately examined by wet mount microscopy, a second swab w as placed in Kupferberg's Trichosel medium for cultivation, and two swabs w ere placed in phosphate-buffered saline (PBS), pH 7.2. The resulting PBS su spension was used for direct staining with acridine orange and fluorescence microscopy, inoculation of modified Diamond's culture medium, and a PCR sp ecific for T. vaginalis, A total of 70 samples positive in one or more of t he tests were identified: 31 (3.8%) infections were detected by,vet mount m icroscopy, and 36 (4.4%) were identified by acridine orange staining, as op posed to 40 (4.9%) and 46 (5.7%) positives in modified Diamond's and Tricho sel media, respectively. PCR was positive for 61 (7.5%) samples. Secondly, from each of 200 women were obtained a urine sample and a vaginal cotton sw ab specimen, and 200 urine samples were obtained from men. For the women, 1 5 (7.4%) of the samples showed a positive result for either the wet mount ( n = 1), Trichosel culture (n = 6), PCR on the vaginal swab sample (It = 10) , or PCR on the urine specimen (n = 11). Four men (2%) were diagnosed with a T. vaginalis infection. Thus, PCR appears to be the method of choice for the detection of genital infections with T, vaginalis.