eWe developed a new Boson chemiluminescence immunoassay (CIA) and evaluated its application with cross-sectional analyses. Our results indicated that the Boson CIA demonstrated strong discriminatory power in diagnosing syphilis and that it can be used as a first-line screening test for syphilis serodiagnosis using the European Centre for Disease Prevention and Control algorithm or as a confirmatory test when combined with a patient's clinical history.T reponema pallidum causes syphilis and can be cultured in vivo only; thus, serological testing remains the mainstay for diagnosing syphilis (1). Currently, three algorithms for syphilis serodiagnosis exist, the traditional algorithm, the reverse algorithm, and the European Centre for Disease Prevention and Control (ECDC) algorithm (2, 3). The ECDC algorithm begins with a reactive treponemal screening followed by a second and different treponemal assay as a confirmatory test; a nontreponemal test is not used (2, 3). In a previous study, we proved that the ECDC algorithm demonstrated good performance for serological syphilis testing (2). In addition, the implementation of automated treponemal assays (e.g., enzyme immunoassays [EIA] and chemiluminescence immunoassays [CIA]) (4) has allowed clinical laboratories to meet increased demands for syphilis testing, increase their efficiency, and provide objective results (5). Thus, an increasing number of clinical laboratories have begun to use the ECDC algorithm (2, 6). However, some commercially automated treponemal tests produce high false-positive rates when used as a first-line screening test, leading to unpleasant situations for patients, overtreatment, and potentially higher costs (7). Hence, a novel highly sensitive and specific treponemal assay as the firstline screening test is a prerequisite for the ECDC algorithm. In this study, we developed a new two-step double-antigen sandwich Boson CIA (Boson Biotechnology Co., Ltd., Xiamen, China) and evaluated its diagnostic performance by conducting cross-sectional analyses.Between December 2011 and May 2014, 37,146 patients underwent syphilis testing in Zhongshan Hospital (Xiamen, China). Syphilis was clinically diagnosed according to Centers for Disease Control and Prevention (CDC) (8) and ECDC guidelines (3) by combining laboratory diagnosis and patient disease history, including clinical characteristics and/or patient sexual history, as demonstrated in our previous studies (2, 9). Each sample was also independently and blindly analyzed using the Treponema pallidum particle agglutination (TPPA) assay (Fujirebio, Tokyo, Japan) and the Boson CIA according to the manufacturers' instructions. Statistical analyses were performed using SPSS v.17 for Windows.Among the 37,146 subjects, 4,026 were diagnosed with syphilis, and the prevalence of syphilis was 10.84% (4,026/37,146). To evaluate the diagnostic accuracy of the Boson CIA, we first used clinical diagnosis as the gold standard. Our results indicated that the sensitivity, specificity, positive predictive value (PPV), and ...
