Although discrimination between primary and secondary dengue infections can be performed using commercially available immunoassays or in-house tests, the evaluation of these methods is important, but is often problematic due to incomplete clinical data. In many cases, patients’ sera submitted to the laboratory may not include the date of onset of illness which is necessary to discriminate primary and secondary dengue infections. This study reports improvement of an in-house capture ELISA using IgG avidity to discriminate primary and secondary dengue virus infection. Modified definition criteria were applied to characterize 99 single sera based on their IgM/IgG ratios. Regressive analysis indicated that the avidity test results (avidity index of 60 % as cutoff) for the discrimination showed good agreement (96 %) and a high correlation (r = −0.81) with those of the in-house capture ELISA (IgM/IgG ratio at 1.2 as cutoff). To further evaluate the in-house tests, 318 convalescent sera were compared with a Focus Diagnostics’ anti-dengue IgM ELISA. Compared with the Focus Diagnostics system, the sensitivity of an in-house IgM determination was 83 %, whereas using both IgM and IgG capture ELISAs the sensitivity increased to 95 %.

尽管可以使用市售的免疫分析或内部测试来区分原发性和继发性登革热感染，但对这些方法的评估很重要，但由于临床数据不完整，往往存在问题。在许多情况下，提交给实验室的患者血清可能不包括区分原发性和继发性登革热感染所必需的发病日期。该研究报告了使用 IgG 亲和力来区分原发性和继发性登革热病毒感染的内部捕获 ELISA 的改进。基于 IgM/IgG 比率，应用修改后的定义标准来表征 99 种单一血清。回归分析表明，区分的亲和力测试结果（60% 的亲和力指数作为临界值）显示出良好的一致性 (96%) 和高相关性 (r = -0. 81) 与内部捕获 ELISA 的那些（IgM/IgG 比率为 1.2 作为截止值）。为了进一步评估内部测试，将 318 份恢复期血清与 Focus Diagnostics 的抗登革热 IgM ELISA 进行了比较。与 Focus Diagnostics 系统相比，内部 IgM 测定的灵敏度为 83%，而同时使用 IgM 和 IgG 捕获 ELISA 的灵敏度提高到 95%。