Sistema FMUSP-HC: Faculdade de Medicina da Universidade de São Paulo (FMUSP) e Hospital das Clínicas da FMUSPARAI, CarolinaLEMOS-MACHADO, Juliano AlvesAUN, Marcelo VivoloBONET-BUB, CarolinaSANTOS, Leandro DinalliMIRANDA, Angelica EspinosaAVELINO-SILVA, Vivian I.2024-02-152024-02-152023BRAZILIAN JOURNAL OF INFECTIOUS DISEASES, v.27, n.6, article ID 103689, 4p, 20231413-8670https://observatorio.fm.usp.br/handle/OPI/58069Rapid Diagnostic Tests (RDT) are useful to identify syphilis cases, particularly for hard-to-reach populations and if laboratory services are scarce. However, RDT performance may be subopti-mal. We aimed to assess the sensitivity and specificity of a syphilis RDT using well-characterized blood donors' samples. We categorized samples from 811 blood donors into five groups: 1 - Sam-ples with reactive Chemiluminescence (QML), FTA-Abs, and VDRL; 2 -Samples with reactive QML and FTA-Abs, and nonreactive VDRL; 3 -Samples with reactive QML, and nonreactive for other markers (false-positives); 4 -Controls with nonreactive QML; and 5 -Samples reactive for HIV, with nonreactive QML. Sensitivity was tested in groups 1 (overall and according to VDRL titers) and 2; specificity was tested in groups 3-5. The RDT had high specificity, even in samples reactive for HIV. The sensitivity was high (91.9%) in samples with reactive VDRL but varied between 75.0%-100% according to VDRL titers. The overall sensitivity was lower (81.3%) in sam-ples with reactive FTA-Abs and nonreactive VDRL. The RDT is a useful tool to detect active syph-ilis but may be more limited for cases with very early or remote infection, or those with prior treatment. When higher sensitivity is needed, additional strategies including recurrent testing or laboratory-based tests may be required.(c) 2023 Sociedade Brasileira de Infectologia.engopenAccessSyphilisSyphilis serodiagnosisSensitivity and speci ficityPoint-of-care testingsexarticleCopyright ELSEVIER BRAZIL10.1016/j.bjid.2023.103689Infectious Diseases1678-4391