Serologic diagnosis of syphilis: comparison of different diagnostic methods

Diagnostic and therapeutic approaches in syphilis show wide variation. The use of only one type of serologic test is insufficient for diagnosis. However, current international recommendations cannot be applied due to various reasons (cost, availability, etc.). The aim of the study was to review serologic data of syphilis patients to determine diagnostic performance of three different methods. In 117 patients suspected of having syphilis, syphilis was diagnosed serologically and clinically. Three different methods were used for detection of antibodies: Rapid Plasma Reagin (RPR), Treponemal Chemiluminescence Microparticle Enzyme Immunoassay (CMIA) and Treponema pallidum hemagglutination (TPHA). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated for the former two methods against TPHA. The sensitivity of RPR and CMIA against TPHA was 58% and 98%, respectively. The specificity of RPR and CMIA against TPHA was 0% and 100%, respectively. Automated enzyme immunoassay systems could contribute to reducing errors that depend on the person, especially while monitoring titration changes.