Application of PCR in Diagnosis of Primary Syphilis

Objective To improve the sensitivity and specificity in diagnosis of primary syphilis. Methods Treponema pallidum PCR was performed to amplify the specific fragment of DNA polymeraseⅠgene (polA), 385 samples of genital ulcer secretions were detected by PCR; meanwhile, the dark-field microscopy and Tp ELISA were applied to detect the secretions and serum specimens from the same patients respectively. Results Of the 385 tests performed, positive PCR results were obtained for 75 patients. The sensitivity and specificity of PCR were 74.5% and 99.3%, respectively. There were statistically significant differences between PCR and dark-field microscopy, Tp ELISA. Conclusions The T. pallidum PCR test is fast, efficient, and reliable. It is a useful addition to serology for the diagnosis of primary syphilis.