The object of this study was to determine the diagnostic performance of four commercially available IgM tests in the diagnosis of measles virus (MeV) primary infection and cases with a serological profile indicating reinfection. Sera from 187 patients with MeV primary infection, 30 patients with suspected reinfection (after vaccine failure), and 153 patients with rash-like symptoms after exclusion of MeV infection were retested with four IgM tests. MeV infection was verified by reverse transcriptase PCR (RT-PCR), and primary and suspected reinfections were differentiated by IgG avidity and neutralization assays. All IgM assays displayed significant agreement (Cohen’s κ, ≥0.604; all P < 0.001) and a higher diagnostic accuracy in primary infection than in suspected reinfection (indicated by high IgG avidity and significantly higher anti-MeV-IgG and neutralizing titers). In the overall cohort, the areas under the curve (AUC) were comparable among all tests, ranging from 0.875 to 0.931, with ranges increasing to 0.911 to 0.930 in the primary infection and decreasing to 0.765 to 0.940 in the setting of high anti-MeV-IgG avidity, and all tests displayed high specificity (81.1 to 92.2%). Of note, IgM tests with the highest diagnostic accuracy had discriminatory abilities not significantly different than PCR from serum. Although reinfections pose a challenge for IgM testing, IgM assays remain a cornerstone in the diagnosis of MeV infections. Especially in samples with a serological profile indicating reinfections, IgM tests displayed an equal or even superior diagnostic ability compared to PCR from serum.

中文翻译：

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四种IgM抗体检测在诊断麻疹病毒原发感染和血清学指标重新感染病例中的性能

这项研究的目的是确定四种市售的IgM检测在诊断麻疹病毒（MeV）原发感染以及血清学特征表明再次感染的病例中的诊断性能。用4项IgM测试对187例MeV原发感染患者，30例疑似再感染（疫苗失败后）和153例MeV排除后出现皮疹样症状的患者的血清进行了重新检测。通过逆转录酶PCR（RT-PCR）验证了MeV感染，并通过IgG亲和力和中和测定区分了原发性和可疑的再感染。所有IgM分析均显示出显着一致性（Cohenκ，≥0.604；所有P<0.001），并且与可疑的再感染相比，原发感染的诊断准确性更高（这表明IgG亲和力高，抗MeV-IgG和中和效价明显更高）。在整个队列中，曲线下面积（AUC）在所有测试中均具有可比性，范围从0.875至0.931，在初次感染中范围增加至0.911至0.930，在高抗MeV的情况下减小至0.765至0.940 -IgG亲和力，所有测试均显示出高特异性（81.1％至92.2％）。值得注意的是，具有最高诊断准确度的IgM测试的区分能力与从血清中进行的PCR并无显着差异。尽管再感染对IgM检测提出了挑战，但IgM检测仍是诊断MeV感染的基石。特别是在血清学特征表明存在再感染的样品中，