Rapid 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 suboptimal. 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 - Samples 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 samples with reactive FTA-Abs and nonreactive VDRL. The RDT is a useful tool to detect active syphilis 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.

快速诊断测试 (RDT) 对于识别梅毒病例非常有用，特别是对于难以接触到的人群以及实验室服务稀缺的情况。然而，RDT 性能可能不是最优的。我们的目的是使用充分表征的献血者样本来评估梅毒 RDT 的敏感性和特异性。我们将 811 名献血者的样本分为五组： 1 - 具有反应性化学发光 (QML)、FTA-Ab 和 VDRL 的样本；2 - 具有反应性 QML 和 FTA-Ab 以及非反应性 VDRL 的样品；3 - 具有反应性 QML 且对其他标记物无反应的样本（假阳性）；4 - 使用非反应式 QML 进行控制；5 - 对 HIV 具有反应性的样品，具有非反应性 QML。在第 1 组（总体并根据 VDRL 滴度）和第 2 组中测试了灵敏度；在第 3-5 组中测试了特异性。即使是对 HIV 具有反应性的样本，RDT 也具有很高的特异性。具有反应性 VDRL 的样品的灵敏度很高 (91.9%)，但根据 VDRL 滴度的不同，灵敏度在 75.0%−100% 之间变化。具有反应性 FTA-Ab 和非反应性 VDRL 的样品的总体敏感性较低 (81.3%)。RDT 是检测活动性梅毒的有用工具，但对于非常早期或远期感染的病例或之前接受过治疗的病例可能更为有限。当需要更高的灵敏度时，可能需要额外的策略，包括反复测试或基于实验室的测试。