Accuracy of Point-of-Care Tests for Syphilis Analyzed

A major change in approach to syphilis testing has been called for which recommends replacing first-line laboratory tests with point-of-care tests (POC) tests globally, especially in resource-limited settings.

An international team, led by scientists at McGill University Health Center (Montreal, QC, Canada) has demonstrated that rapid POC tests for syphilis are as accurate as conventional laboratory tests. Currently, syphilis is screened using conventional laboratory-based tests that can take up to three weeks to deliver results. These tests require chemical agents, trained staff, and a continuous supply of electricity, which are not readily available in some parts of the world. Rapid and POC tests can be performed on a simple finger stick sample one patient at a time, and the results communicated to the patient within 20 minutes, saving time and helping doctors order confirmatory tests and rapidly flagging patients who need treatment.

The team identified 18 rapid and POC tests in global use in a meta-analysis. The vast majority were immunochromatographic strip (ICS) based assays with most tests being Determine (Abbott Diagnostics; Maidenhead, UK) at 29% (38/131); SD Biolines (Standard Diagnostics; Seoul, South Korea) at 18% (23/131); VisiTect (Omega Diagnostics; Alva, UK) at 16% (21/131); and Syphicheck (Qualpro; Goa, India) at 15% (19/131). In whole blood sample, using a Treponema pallidum (TP) specific reference standard, under the imperfect reference standard assumption, sensitivity and specificity estimates for Determine was 86.3% and 95.9%; for SD Bioline was 84.5% and 98.0%; for Syphicheck was 74.5% and 99.6%; and for VisiTect was 74.3% and 99.4%.

Nitika Pant Pai, MD, MPH, PhD, a lead author of the study said, “Our study has major worldwide implications for populations living in rural areas with limited access to healthcare. These tests offer the potential to expedite first line screening in settings where people have no access to a primary care physician or where laboratories take more than a week to deliver results." The study was published on February 26, 2013, in the journal Public Library of Science ONE.

Related Links:
McGill University Health Center
Abbott Diagnostics
Standard Diagnostics