Rapid Diagnostic Tests For Syphilis, Yaws, Less Sensitive With Lower Antibody Titers

A rapid diagnostic test to detect syphilis and yaws has good sensitivity and specificity, but sensitivity may decrease with lower antibody titers, according to a study published online in Clinical Infectious Diseases.

Michael Marks, Msc, of the Clinical Research Department, London School of Hygiene & Tropical Medicine, and colleagues looked at data from the Dual Path Platform (DPP) Syphilis Screen & Confirm test, which includes both treponemal and nontreponemal components.

Using PubMed, the researchers searched data published between 1960 and 2015 and found 9 studies that included 7267 tests. They noted that in both components, those patients with higher titer rapid plasma reagins had better sensitivities compared with those with lower-titer group (98.2% vs. 90.1%; P < .0001 in the trepomenal and (98.2% vs. 80.6%; P < .0001 in the nontrepomenal groups. 

The researchers noted that although the entire individual clinical dataset was unavailable for one study, their findings suggest that “combined treponemal–nontreponemal assays offer a number of advantages over treponemal only rapid diagnostic tests.” 

Reference

1. Marks M, Yin YP, Che XS, et al.  Metaanalysis of the Performance of a Combined Treponemal and Nontreponemal Rapid Diagnostic Test for Syphilis and Yaws. Clin Infect Dis J. 2016; doi: 10.1093/cid/ciw348.