Evaluation of Eight Rapid Screening Tests for Acute Leptospirosis in Hawaii

Leptospirosis is a major public health problem throughout the world. Clinical recognition of leptospirosis is challenging, and the definitive serologic diagnostic assay, the microscopic agglutination test, is time-consuming and difficult to conduct. Various serologic screening tests have been developed, but their performance among ill persons in the United States has not been established. Eight screening tests were compared using 379 serum samples obtained in 1998 and 1999 from a series of 236 patients (33 with confirmed infection). The median number of days between illness onset and specimen collection was 9. The overall sensitivity, by specimen, for each test was as follows: indirect hemagglutination assay (MRL Diagnostics, Cypress, Calif.), 29%; INDX Leptospira Dip-S-Tick (PanBio InDx, Inc., Baltimore, Md.), 52%; Biognost IgM IFA test (Bios GmbH Labordiagnostik, Gräfelfing, Germany), 40%; Biolisa IgM ELISA (Bios GmbH, Labordiagnostik), 48%; Leptospira IgM ELISA (PanBio Pty Ltd., Brisbane, Australia), 36%; SERION ELISA classic Leptospira (Institut Virion•Serion GmbH, Würzburg, Germany), 48%; LEPTO Dipstick(Organon-Teknika, Ltd., Amsterdam, The Netherlands), 34%; Biosave latex agglutination test (LATEX; Bios GmbH Labordiagnostik), 86%. Test specificity ranged from 85 to 100% among all tests except LATEX, for which the specificity was significantly lower, at 10%. Test sensitivity was particularly low (<25%) for all tests (except LATEX) on specimens collected during the first week of illness. This is the most comprehensive field trial of leptospirosis screening tests reported to date. The data indicate that immunoglobulin M detection tests have limited utility for diagnosing leptospirosis during the initial evaluation of patients seen in Hawaii, a time when important therapeutic decisions are made. Improved leptospirosis screening tests are needed.钩端螺旋体病（Leptospirosis）是全球范围内的重大公共卫生问题。钩端螺旋体病的临床识别颇具挑战性，而其确诊血清学检测方法——显微镜凝集试验（microscopic agglutination test）——不仅耗时，且操作难度较大。目前已开发出多种血清学筛查检测方法，但尚未明确其在美国患者群体中的检测效能。本研究以1998年至1999年采集的379份血清样本为研究对象，样本来自236例患者（其中33例经确诊感染钩端螺旋体病），并对8种筛查检测方法进行了对比评估。患者发病至样本采集的中位天数为9天。按样本统计的各项检测的总体灵敏度如下：间接血凝试验（indirect hemagglutination assay，MRL Diagnostics，美国加利福尼亚州赛普里斯市）：29%；INDX Leptospira Dip-S-Tick检测（PanBio InDx, Inc.，美国马里兰州巴尔的摩市）：52%；Biognost IgM免疫荧光试验（Bios GmbH Labordiagnostik，德国格雷费尔芬市）：40%；Biolisa IgM酶联免疫吸附试验（ELISA，Bios GmbH Labordiagnostik）：48%；钩端螺旋体IgM酶联免疫吸附试验（ELISA，PanBio Pty Ltd.，澳大利亚布里斯班）：36%；SERION经典钩端螺旋体酶联免疫吸附试验（ELISA，Institut Virion•Serion GmbH，德国维尔茨堡市）：48%；LEPTO快速检测试纸（Organon-Teknika, Ltd.，荷兰阿姆斯特丹市）：34%；Biosave乳胶凝集试验（LATEX，Bios GmbH Labordiagnostik）：86%。除LATEX外，其余各项检测的特异度介于85%至100%之间；而LATEX的特异度显著更低，仅为10%。对于发病第一周采集的样本，除LATEX外的所有检测方法的灵敏度均极低（<25%）。本研究是目前已报道的最为全面的钩端螺旋体病筛查检测现场试验。研究数据显示，在夏威夷地区患者的初始诊疗阶段——即需作出关键治疗决策的时期——，免疫球蛋白M（IgM）检测试剂对钩端螺旋体病的诊断价值有限。亟需开发更优质的钩端螺旋体病筛查检测方法。