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

Abstract

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.

Maternal and congenital syphilis in rural Haiti

“…This test takes 10-15 minutes, so women who test positive are able to receive the first dose of intramuscular penicillin treatment on the day of testing. The Determine-TP rapid test (Inverness, Waltham, Massachusetts, United States of America) has been validated in several studies as an appropriate screening tool for low-resource areas (17)(18)(19)(20).…”

Laboratorial Diagnosis of Syphilis

“…The assay is performed with 50 uL of whole blood or 25 uL of serum or plasma, and results can be read in 15 minutes. For serum samples, sensitivities were 84.2% to 98.2% and specificities 98.0% to 99.1% (Herring et al, 2006;Mabey et al, 2006a). For whole blood samples, sensitivities were 77.9% to 98.2% and 72.7% to 96.1% respectively for laboratory and local clinic testing, while overall specificities were around 99% for both settings (Herring et al, 2006;Mabey et al, 2006a).…”

“…Overall, rapid tests are highly sensitive and specific. The World Health Organization compared the performance of 8 rapid tests to a combined reference standart TPHA/TPPA, reporting sensitivities of 84.5%-97.7% and specificities of 92.8% -98% (Herring et al, 2006). A lower sensitivity was found for a whole blood in comparison with serum or plasma.…”

“…Determine Syphilis TP (Abbott) has recombinant antigen TpN47 immobilized on nitrocellulose strips and use 50uL of sample, either whole blood, serum or plasma and results can be read in 5 to 20 minutes. For serum or plasma specimens, sensitivity range were 93.7 to 99.2% and specificity 92.4 to 100% (Diaz et al, 2004;Herring et al, 2006;Mabey et al, 2006a;Mabey et al, 2006b;Oshiro et al, 1999;Sato et al, 2003). For whole blood sample, the sensitivity ranged from 85,9% to 95.0%, and specificity was higher than 97.7% (Gianino et al, 2007;Mabey et al, 2006a;Siedner et al, 2004;Tinajeros et al, 2006) when performed in the reference laboratory.…”

“…For whole blood sample, the sensitivity ranged from 85,9% to 95.0%, and specificity was higher than 97.7% (Gianino et al, 2007;Mabey et al, 2006a;Siedner et al, 2004;Tinajeros et al, 2006) when performed in the reference laboratory. Lower sensitivity of 75.6% was found when the assay was performed at local clinic (Li et al, 2009;Mabey et al, 2006a (Herring et al, 2006;Mabey et al, 2006a;Montoya et al, 2006). Visitec Syphilis (Omega Diagnostics, Scotland UK) uses two recombinant antigens TpN17 and TpN47 to capture specific antibodies.…”