A retrospective observational comparative study of VDRL vs. TPHA and their role in serodiagnosis of syphilis in a tertiary care centre

Abstract

Background: Syphilis is difficult to diagnose challenging the clinicians. Combined use of both non treponemal and treponemal serological tests will give correct diagnosis of syphilis.The aim of the study was to evaluate the role of VDRL and TPHA in the serodiagnosis of syphilis.Methods: Open label retrospective study done in the department of dermatology of a tertiary care centre after getting IEC approval. One hundred and seventy patients’ serological reports done for syphilis during the month January 2017 to May 2017 were taken for the study and were analysed retrospectively after categorizing into three groups. Frequency and percentage of patients who were reactive to VDRL, weakly reactive to VDRL, positive for prozone phenomenon and reactive to TPHA were noted in each group and analysed statistically.Results: In our study two cases showed biological false positive results in group 1 and three cases in group 3 were biological false reactors. In our study five patients in group 1 and three patients in group 3 were non-reactive to VDRL but were reactive to TPHA due to the presence of Ig G antibodies and all these patients gave a past history of treatment of syphilis. Conclusions: Our study was successful in evaluating the role of TPHA and VDRL in the sero-diagnosis of syphilis. The VDRL and TPHA being simple and economical tests can be combined in the assessment of syphilis and ensures that no cases are missed.