COMPARATIVE EVALUATION OF RAPID PLASMA REAGIN, ENZYME-LINKED IMMUNOSORBENT ASSAY, AND CHEMILUMINESCENCE IMMUNOASSAY FOR THE DIAGNOSIS OF SYPHILIS AMONG VOLUNTARY BLOOD DONORS

Abstract

Introduction: Syphilis remains a significant transfusion-transmissible infection requiring accurate screening among blood donors¹,².

Aim: To compare the diagnostic performance of Rapid Plasma Reagin (RPR) and Chemiluminescence Immunoassay (CLIA) with Enzyme-Linked Immunosorbent Assay (ELISA).

Materials and Methods: A cross-sectional study was conducted among 185 voluntary blood donors at a tertiary care center in Chennai from August 2024 to February 2026. Samples were tested using RPR, ELISA, and CLIA. Statistical analysis included Chi-square test and kappa statistics.

Results: Seropositivity was highest with CLIA (16.8%), followed by ELISA (9.7%) and RPR (5.9%). A strong association was observed between ELISA and RPR (p < 0.001; kappa = 0.590). CLIA showed a significant association with ELISA (p < 0.001) but only fair agreement (kappa = 0.325).

Conclusion: CLIA demonstrated superior sensitivity and higher detection rates compared to ELISA and RPR, making it a valuable screening tool for blood donors.