A multi-centre evaluation of nine rapid, point-of-care syphilis tests using archived sera

Objectives: To evaluate nine rapid syphilis tests at eight geographically diverse laboratory sites for their performance and operational characteristics. Methods: Tests were compared "head to head'' using locally assembled panels of 100 archived ( 50 positive and 50 negative) sera at each site using as reference standards the Treponema pallidum haemagglutination or the T pallidum particle agglutination test. In addition inter-site variation, result stability, test reproducibility and test operational characteristics were assessed. Results: All nine tests gave good performance relative to the reference standard with sensitivities ranging from 84.5-97.7% and specificities from 84.5-98%. Result stability was variable if result reading was delayed past the recommended period. All the tests were found to be easy to use, especially the lateral flow tests. Conclusions: All the tests evaluated have acceptable performance characteristics and could make an impact on the control of syphilis. Tests that can use whole blood and do not require refrigeration were selected for further evaluation in field settings.