Comparison Study of Semi-Quantitative RPR Test and Tpha for Serodiagnosis of Syphilis at a Tertiary Care Hospital, Udaipur, Rajasthan

Abstract

Areactive RPR should always be conrmed with treponemal test like TPHAin suspected syphilis patients to rule out biological false positive cases. It is important to nd an alternative to TPHA as it is frequently not available in resource limited health care facilities of developing nations like India. Aim:Aim of our study is to evaluate semi-quantitative RPR test and TPHAin serological diagnosis of syphilis in resource limited health care facilities. Methodology: A retrospective cross sectional study from January 2020 to December 2021 was conducted on 116 suspected cases of syphilis. All cases were tested for qualitative RPR test, semi-quantitative RPR test ant TPHA test. Serum samples that are positive in qualitative RPR test but negative in TPHAwere referred to as biologic falsepositive (BFP) reactions. Results:We found 32 (27.58%) biological false positive (BFP) cases in dilutions 1:8 or below on semi quantitative RPR test. No BFP case was found in dilutions 1:16 or more. BFP can occur in any age group. We have noted that female 25(21.55%) were showing more BFP cases in our study. Conclusions: No biological false positive reaction has been found in above 1:8 dilution of RPR test. Semi-quantitative RPR test results in 1:16 or more dilution is equivalent to TPHAresults for diagnosis of syphilis.