Diagnosis of trichomonas vaginalis by PCR method

Trichomonas vaginalis is the most prevalent nonviral sexually transmitted disease in the world. Traditionally physicians make the diagnosis based on clinical grounds. Characteristics of the vaginal discharge, including color combination is not sufficient to diagnose trichomonas vaginalis infection reliably and laboratory diagnosis is necessary. In this study, a PCR targeting the beta-tubulin genes of the trichomonas vaginalis was developed for the detection of the organism in the vaginal swab samples. A vaginal swab specimen was obtained from 24 women visiting the women clinic of Shahid-Beheshti hospital of the Isfahan University of Medical Sciences. Each specimen was divided into two sections. One section was immediately examined by wet preparation microscopy test and the other section was placed in phosphate-buffered saline and transferred to biotechnology laboratory of Isfahan University of Medical Sciences, and the resulting suspension was used for a PCR reaction, specific for the trichomonas vaginalis. 24 samples were divided into two groups of 8 and 16 samples. The first group was examined by wet preparation microscopy and PCR tests. The second group was analyzed by clinical observation and PCR test. Specimens that were obtained from the first group had a positive test for both wet preparation and PCR test. In the second group, from the 16 specimens that were analyzed, 6 and 8 samples showed positive results with PCR and clinical observation, respectively. The results of this study indicate the high specificity of PCR method in detecting trichomonas vaginalis. The specificity of PCR method is similar to wet preparation. But the clinical observation is not sensitive enough to be used alone for diagnosing the parasite.