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

They noted that in both components, those patients with higher titer rapid plasma reagins had better sensitivities compared with those with lower-titer group.

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.