Laboratory evaluation of four HIV/syphilis rapid diagnostic tests

Background Sexually transmitted infections, such as HIV and syphilis, are one of the major health care problems worldwide, especially in low- and middle income countries. HIV screening programmes have been widely used for many years. The introduction of rapid point-of-care tests (RDTs) that can detect both HIV and syphilis, using one single blood specimen, would be a promising tool to integrate the detection of syphilis into HIV programmes and so improve the accessibility of syphilis testing and treatment. Methods As part of the World Health Organization pre-qualification of in vitro diagnostics assessment, the laboratory performance of four dual HIV-Syphilis rapid diagnostic tests (SD Bioline HIV/Syphilis Duo, DPP HIV-Syphilis Assay, Multiplo Rapid TP/HIV Antibody Test and Insti Multiplex HIV-1/HIV-2/Syphilis Antibody Test) was assessed using a well characterized multiregional panel of stored sera specimens. Results In total 400 specimens were tested with each assay, resulting in excellent sensitivities and specificities for HIV, ranging from 99.5 to 100% and from 93.5 to 99.5%, respectively. Results obtained for the Treponema pallidum antibodies were lower, with the lowest sensitivity of 73.5% for Multiplo and the highest of 87% for SD Bioline. Specificities ranged from 99.0 to 100%. Conclusion Although these results suggest that the tests could further improve in accuracy in detection of treponemal antibodies, their introduction into screening programmes to increase the accessibility of HIV/Syphilis diagnosis and treatment for difficult to reach populations in the world is promising.