Mboloi M M, Bekker C P, Kruitwagen C, Greiner M, Jongejan F
Department of Parasitology and Tropical Veterinary Medicine, and Center for Biostatistics, Utrecht University, Utrecht, The Netherlands.
Clin Diagn Lab Immunol. 1999 Jan;6(1):66-72. doi: 10.1128/CDLI.6.1.66-72.1999.
The major antigenic protein 1 fragment B (MAP1-B) enzyme-linked immunosorbent assay (ELISA) for the diagnosis of Cowdria ruminantium infections was validated to determine cutoff values and evaluate its diagnostic performance with sheep and goat sera. Cowdria-infected populations consisted of 48 sheep and 44 goats, while the noninfected populations consisted of 64 sheep and 107 goats. Cutoff values were determined by two-graph receiver-operating characteristic (TG-ROC) curves. The cutoff value was set at 31 and 26.6% of the positive control reference samples for sheep and goat sera, respectively. The test's diagnostic performance was evaluated with measurements of the area under the concentration-time curve (AUC) of the ROC curves and by the valid range proportion (VRP). The AUCs were 0.978 for sheep sera and 0.989 for goat sera. The VRP for both sheep and goat sera was approximately 1.0. The intermediate range (IR), which defines results that are neither positive nor negative, was 0 for goat sera and 2.81 for sheep sera. In an ideal test, the AUC and VRP would be 1.0 and the IR would be 0. In this study these parameters were close to those of an ideal test. It is concluded that the MAP1-B ELISA is a useful test for the diagnosis of C. ruminantium infection in small ruminants.
用于诊断反刍兽立克次氏体感染的主要抗原蛋白1片段B（MAP1-B）酶联免疫吸附测定（ELISA）经过验证，以确定临界值，并使用绵羊和山羊血清评估其诊断性能。感染反刍兽立克次氏体的群体包括48只绵羊和44只山羊，而未感染群体包括64只绵羊和107只山羊。临界值通过双图受试者工作特征（TG-ROC）曲线确定。绵羊和山羊血清的临界值分别设定为阳性对照参考样品的31%和26.6%。通过测量ROC曲线的浓度-时间曲线下面积（AUC）和有效范围比例（VRP）来评估该检测的诊断性能。绵羊血清的AUC为0.978，山羊血清的AUC为0.989。绵羊和山羊血清的VRP均约为1.0。定义既非阳性也非阴性结果的中间范围（IR），山羊血清为0，绵羊血清为2.81。在理想检测中，AUC和VRP应为
