Coetzer Andre, Sabeta Claude T, Markotter Wanda, Rupprecht Charles E, Nel Louis H
Department of Microbiology and Plant Pathology, University of Pretoria, Gauteng, South Africa.
Agricultural Research Council-Onderstepoort Veterinary Institute, Rabies Division, Gauteng, South Africa.
PLoS Negl Trop Dis. 2014 Sep 25;8(9):e3189. doi: 10.1371/journal.pntd.0003189. eCollection 2014 Sep.
The major etiological agent of rabies, rabies virus (RABV), accounts for tens of thousands of human deaths per annum. The majority of these deaths are associated with rabies cycles in dogs in resource-limited countries of Africa and Asia. Although routine rabies diagnosis plays an integral role in disease surveillance and management, the application of the currently recommended direct fluorescent antibody (DFA) test in countries on the African and Asian continents remains quite limited. A novel diagnostic assay, the direct rapid immunohistochemical test (dRIT), has been reported to have a diagnostic sensitivity and specificity equal to that of the DFA test while offering advantages in cost, time and interpretation. Prior studies used the dRIT utilized monoclonal antibody (MAb) cocktails. The objective of this study was to test the hypothesis that a biotinylated polyclonal antibody (PAb) preparation, applied in the dRIT protocol, would yield equal or improved results compared to the use of dRIT with MAbs. We also wanted to compare the PAb dRIT with the DFA test, utilizing the same PAb preparation with a fluorescent label. The PAb dRIT had a diagnostic sensitivity and specificity of 100%, which was shown to be marginally higher than the diagnostic efficacy observed for the PAb DFA test. The classical dRIT, relying on two-biotinylated MAbs, was applied to the same panel of samples and a reduced diagnostic sensitivity (83.50% and 90.78% respectively) was observed. Antigenic typing of the false negative samples indicated all of these to be mongoose RABV variants. Our results provided evidence that a dRIT with alternative antibody preparations, conjugated to a biotin moiety, has a diagnostic efficacy equal to that of a DFA relying on the same antibody and that the antibody preparation should be optimized for virus variants specific to the geographical area of focus.
狂犬病的主要病原体——狂犬病病毒（RABV），每年导致数万人死亡。这些死亡大多与非洲和亚洲资源有限国家的犬类狂犬病传播循环有关。尽管常规狂犬病诊断在疾病监测和管理中起着不可或缺的作用，但目前推荐的直接荧光抗体（DFA）检测在非洲和亚洲大陆国家的应用仍然非常有限。据报道，一种新型诊断检测方法——直接快速免疫组织化学检测（dRIT），其诊断敏感性和特异性与DFA检测相当，同时在成本、时间和判读方面具有优势。先前的研究使用了单克隆抗体（MAb）混合物的dRIT。本研究的目的是检验以下假设：在dRIT方案中应用生物素化多克隆抗体（PAb）制剂，与使用MAb的dRIT相比，将产生同等或更好的结果。我们还想用相同的荧光标记PAb制剂，将PAb dRIT与DFA检测进行比较。PAb dRIT的诊断敏感性和特异性均为100%，略高于PAb DFA检测的诊断效能。将依赖两种生物素化MAb的经典dRIT应用于同一组样本，观察到诊断敏感性降低（分别为83.50%和90.78%）。对假阴性样本的抗原分型表明，所有这些样本均为獴RABV变体。我们的结果证明，与生物素部分偶联的替代抗体制剂的dRIT，其诊断效能与依赖相同抗体的DFA相当，并且抗体制剂应针对特定地理区域的病毒变体进行优化。
