Laboratory evaluation of the Chembio Dual Path Platform HIV-Syphilis Assay.

Background: Use of rapid diagnostic tests for HIV and syphilis has increased remarkably in the last decade. As new rapid diagnostic tests become available, there is a continuous need to assess their performance and operational characteristics prior to use in clinical settings.

Objectives: In this study, we evaluated the performance of the Chembio Dual Path Platform (DPP) HIV-Syphilis Assay to accurately diagnose HIV, syphilis, and HIV/syphilis co-infection.

Method: In 2013, 990 serum samples from the Georgia Public Health Laboratory in Atlanta, Georgia, United States were characterised for HIV and syphilis and used to evaluate the platform. HIV reference testing combined third-generation Enzyme Immunoassay and Western Blot, whereas reference testing for syphilis was conducted by the passive particle agglutination method and the TrepSure assay. We assessed the sensitivity and specificity of the DPP assay on this panel by comparing results with the HIV and syphilis reference testing algorithms.

Results: For HIV, sensitivity was 99.8% and specificity was 98.4%; for syphilis, sensitivity was 98.8% and specificity was 99.4%. Of the 348 co-infected sera, 344 (98.9%) were detected accurately by the DPP assay, but 11 specimens had false-positive results (9 HIV and 2 syphilis) due to weak reactivity.

Conclusion: In this evaluation, the Chembio DPP HIV-Syphilis Assay had high sensitivity and specificity for detecting both HIV and treponemal antibodies. Our results indicate that this assay could have a significant impact on the simultaneous screening of HIV and syphilis using a single test device for high-risk populations or pregnant women needing timely care and treatment.