Center for Interdisciplinary Studies in Sexuality, AIDS, and Society, Universidad Peruana Cayetano Heredia, Lima, Peru.
Division of Infectious Diseases, David Geffen School of Medicine, University of California, Los Angelesgrid.19006.3e, Los Angeles, California, USA.
Microbiol Spectr. 2022 Jun 29;10(3):e0264221. doi: 10.1128/spectrum.02642-21. Epub 2022 May 31.
Because syphilis is a public health concern, new strategies and tools for detecting active syphilis cases should be evaluated for future implementation. We assessed the laboratory performance of the DPP Syphilis Screen & Confirm rapid immunodiagnostic test (Chembio Diagnostics, Medford, NY, USA), using visual reading and the manufacturer's electronic test microreader, for detection of treponemal and nontreponemal antibodies in 383 fully characterized stored serum specimens. We used the Treponema pallidum particle agglutination (TPPA) test and rapid plasma reagin (RPR) test as reference tests for the DPP Syphilis Screen & Confirm assay treponemal and nontreponemal components, respectively. The sensitivity values for treponemal antibody detection by electronic reader and visual interpretation were 83.2% and 85.9%, respectively, with 100% specificity. For nontreponemal antibody detection, the sensitivity values were 65.7% and 69.0% and the specificity values were 88.7% and 89.4% for electronic reader and visual interpretation, respectively. There was excellent correlation between visual interpretation and the microreader for either component (kappa coefficient, 0.953). When restricting the analysis to RPR titers of ≥1:8, the sensitivity was 96.9% for either reading method; numerical microreader values showed good correlation with RPR titers (Spearman rho of 0.77). The DPP Syphilis Screen & Confirm assay showed good performance, compared to reference syphilis tests, using serum. Field evaluation studies should be done to validate its use for detection of active cases and for monitoring of treated syphilis patients. Syphilis remains a public health problem; therefore, health systems must incorporate screening tools that allow a rapid and accurate diagnosis to provide adequate treatment. The DPP Syphilis Screen & Confirm Assay simultaneously detects treponemal and nontreponemal antibodies, emerging as an alternative for identifying cases in situations in which there is no infrastructure to perform conventional syphilis testing, but it is necessary to generate evidence regarding the performance of this technology in various scenarios. We found that the test performs well, compared to TPPA and RPR tests, using stored samples from participants at high risk of acquiring syphilis. Additionally, when the Chembio microreader was incorporated, similar results are obtained by the device, compared to those reported by trained laboratory professionals, and correlated with the semiquantitative results of the RPR test. We think that the use of the DPP Syphilis Screen & Confirm Assay with the microreader might help in detecting active syphilis cases and perhaps in monitoring treatment responses in the field.
由于梅毒是一个公共卫生问题，应该评估新的策略和工具来检测活动性梅毒病例，以便将来实施。我们评估了 DPP 梅毒筛查和确认快速免疫诊断试验（Chembio Diagnostics，Medford，NY，USA）的实验室性能，使用视觉阅读和制造商的电子测试微读器，检测 383 个充分特征化的储存血清标本中的梅毒螺旋体和非梅毒螺旋体抗体。我们使用梅毒螺旋体颗粒凝集（TPPA）试验和快速血浆反应素（RPR）试验分别作为 DPP 梅毒筛查和确认试验的梅毒螺旋体和非梅毒螺旋体成分的参考试验。电子阅读器和视觉解释的梅毒螺旋体抗体检测的灵敏度值分别为 83.2%和 85.9%，特异性均为 100%。对于非梅毒螺旋体抗体检测，电子阅读器和视觉解释的灵敏度值分别为 65.7%和 69.0%，特异性值分别为 88.7%和 89.4%。对于任何一种成分，视觉解释与微读器之间均具有极好的相关性（kappa 系数，0.953）。当将分析限制在 RPR 滴度≥1:8 时，两种阅读方法的灵敏度均为 96.9%；数字微读器值与 RPR 滴度显示出良好的相关性（Spearman rho 为 0.77）。与参考梅毒试验相比，DPP 梅毒筛查和确认试验在使用血清时表现出良好的性能。应进行现场评估研究，以验证其用于检测活动性病例和监测治疗后的梅毒患者的用途。梅毒仍然是一个公共卫生问题；因此，卫生系统必须纳入能够快速准确诊断的筛查工具，以提供适当的治疗。DPP 梅毒筛查和确认试验同时检测梅毒螺旋体和非梅毒螺旋体抗体，是在没有基础设施进行常规梅毒检测的情况下识别病例的一种替代方法，但需要生成关于该技术在各种情况下性能的证据。我们发现，与 TPPA 和 RPR 试验相比，该试验在高危感染梅毒的参与者的储存样本中表现良好。此外，当使用 Chembio 微读器时，与经过培训的实验室专业人员报告的结果相比，该设备获得了相似的结果，并与 RPR 试验的半定量结果相关。我们认为，使用 DPP 梅毒筛查和确认试验与微读器可能有助于检测活动性梅毒病例，并可能有助于在现场监测治疗反应。
