METHODS: We conducted a double-blinded assay using 104 serum samples from patients with confirmed or discarded diagnosis for leptospirosis. The diagnostic performance of Lepto-LF was estimated across different ranges of days from onset of symptoms (dpo), considering the diagnostic algorithm as reference standard. Additionally, it was compared with the screening methods enzyme-linked immunosorbent assay (IgM-ELISA) and the slide agglutination test using temperature-resistant antigen (SATR).
RESULTS: Lepto-LF exhibited perfect diagnostic performance with a Youden´s index J = 1 from 6 dpo in the acute phase. IgM-ELISA gave slightly lower accuracy with J = 0.91 and 95.5% of both sensitivity and specificity; while SATR showed a markedly inferior yield (J = 0.41, sensitivity = 95.5%, specificity = 45.5%). The performances remained consistent in the convalescence phase of the disease (> 10 dpo).
CONCLUSIONS: Lepto-LF was found to be a reliable test for simple, rapid and early diagnosis of leptospirosis, resulting a promising tool for decentralizing leptospirosis diagnosis and enabling timely treatment of patients. In addition, Lepto-LF may be employed as confirmatory test, especially in remote areas and vulnerable contexts where the standard MAT is not available.
方法:我们使用104份血清样本进行了双盲分析,这些样本来自确诊或废弃的钩端螺旋体病诊断。Lepto-LF的诊断性能在症状发作(dpo)的不同天数范围内进行估计,将诊断算法作为参考标准。此外,将其与酶联免疫吸附试验(IgM-ELISA)和使用温度抗性抗原(SATR)的载玻片凝集试验进行了比较。
结果:Lepto-LF在急性期表现出完美的诊断性能,从6dpo开始,Youden指数J=1。IgM-ELISA的准确性略低,灵敏度和特异性均为J=0.91和95.5%;而SATR的产量明显较差(J=0.41,灵敏度=95.5%,特异性=45.5%)。在疾病的恢复期(>10dpo)表现保持一致。
结论:发现Lepto-LF是简单,快速和早期诊断钩端螺旋体病,为分散钩端螺旋体病诊断和及时治疗患者提供了有希望的工具。此外,Lepto-LF可以用作确认测试,特别是在标准MAT不可用的偏远地区和易受攻击的环境中。