Rapid point-of-care tests (POC) for syphilis have sensitivities and specificities comparable to conventional laboratory tests, according to a review published online Feb. 26 in PLOS One. The authors say a major change is necessary in syphilis testing strategies and recommend replacing first-line laboratory tests with POC tests globally to expedite screening, particularly in resource-limited settings. “This meta-analysis is important as it includes all global sub populations at risk, thus generating high quality evidence to inform global policy,” write the authors, including Nitika Pant Pai, M.D., Ph.D., from MzcGill University in Canada. The gold standard for syphilis testing is done using two laboratory tests—a non-Treponema pallidum (non-TP) and Treponema pallidum (TP)-specific tests. First-line screening is usually performed with non-TP tests that detect anti-cardiolipin antibodies. These tests are cheaper compared to TP tests, but they can give false positives with malaria, immune disorders, and pregnancy. For positive non-TP results, confirmation testing is performed with a TP-specific test, which is limited in its ability to distinguish past and active infections. The researchers extracted data from 33 articles published from 1980 to 2012 to compare 18 globally used rapid and POC treponemal tests. Four tests accounted for the majority of tests studied in published […]
Rapid point-of-care tests (POC) for syphilis have sensitivities and specificities comparable to conventional laboratory tests, according to a review published online Feb. 26 in PLOS One. The authors say a major change is necessary in syphilis testing strategies and recommend replacing first-line laboratory tests with POC tests globally to expedite screening, particularly in resource-limited settings.
“This meta-analysis is important as it includes all global sub populations at risk, thus generating high quality evidence to inform global policy,” write the authors, including Nitika Pant Pai, M.D., Ph.D., from MzcGill University in Canada.
The gold standard for syphilis testing is done using two laboratory tests—a non-Treponema pallidum (non-TP) and Treponema pallidum (TP)-specific tests. First-line screening is usually performed with non-TP tests that detect anti-cardiolipin antibodies. These tests are cheaper compared to TP tests, but they can give false positives with malaria, immune disorders, and pregnancy. For positive non-TP results, confirmation testing is performed with a TP-specific test, which is limited in its ability to distinguish past and active infections.
The researchers extracted data from 33 articles published from 1980 to 2012 to compare 18 globally used rapid and POC treponemal tests. Four tests accounted for the majority of tests studied in published papers. The Determine (Abbott Diagnostics, United Kingdom) had a sensitivity of 86.3 percent and specificity of 95.9 percent, SD Biolines (Standard, South Korea) had an accuracy of 84.5 percent and 98 percent, Syphicheck (Qualpro, India) had an accuracy of 74.5 percent and 99.6 percent, and VisiTect (Omega Diagnostics, United Kingdom) had an accuracy of 74.3 percent and 99.4 percent.
“Despite being less than 100 percent accurate . . . rapid and POC tests have the potential to facilitate rapid improved detection of syphilis, allowing for treatment initiation in the same visit, reducing missed opportunities for detection and timely intervention to prevent transmission to infants and to partners,” conclude the authors.
