Accuracy of parasitological and immunological tests for the screening of human schistosomiasis in immigrants and refugees from African countries: An approach with Latent Class Analysis
Accuracy of parasitological and immunological tests for the screening of human schistosomiasis in immigrants and refugees from African countries: An approach with Latent Class Analysis
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DOI：
10.1371/journal.pntd.0005593
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发表时间：
2017-06-01
影响因子：
3.8
通讯作者：
Bisoffi, Zeno
中科院分区：
文献类型：
--
作者：
Beltrame, Anna;Guerriero, Massimo;Bisoffi, Zeno
背景血吸虫病是一种被忽视的感染，影响着数百万人，其中大多数生活在撒哈拉以南非洲。慢性感染引起的发病率和死亡率是相关的，尽管血吸虫病在临床上通常是沉默的。已经实施了不同的诊断测试，以改善传统上依赖于灵敏度低的寄生虫学测试的筛查和诊断。本研究的目的是评估不同的测试，在非洲移民血吸虫病的筛查，在非地方性setting.Methodology/Principal findingsA回顾性研究进行了373例患者筛选在中心热带疾病（CTD）在内格拉尔，维罗纳，意大利。生物样本检测：粪便/尿液显微镜，循环阴极抗原（CCA）试纸条试验，ELISA，蛋白质印迹，免疫层析试验（ICT）。主要根据显微镜检查结果（一级参考标准）评估免疫学试验的试验准确度和预测值：ICT和WB的灵敏度最高（分别为94%和92%），NPV较高（98%）。CCA的特异性最高（93%），但敏感性较低（48%）。还使用复合参考标准CRS（在显微镜检查阳性和/或至少2次一致阳性免疫学检测的情况下，将患者分类为感染）和潜在类别分析（LCA）进行分析。后两个模型表现出良好的协议（科恩的kappa值：0.92）的分类结果。事实上，他们都证实ICT是具有最高灵敏度（96%）和NPV（97%）的测试，而且PPV相当好（根据CRS和LCA分别为78%和72%）。ELISA法特异性最高（99%以上）。ICT似乎是一个合适的筛选测试，即使单独使用时。ConclusionsThe快速测试ICT是最敏感的测试，与潜在的被用作一个单一的筛选测试非洲移民。
BackgroundSchistosomiasis is a neglected infection affecting millions of people, mostly living in subSaharan Africa. Morbidity and mortality due to chronic infection are relevant, although schistosomiasis is often clinically silent. Different diagnostic tests have been implemented in order to improve screening and diagnosis, that traditionally rely on parasitological tests with low sensitivity. Aim of this study was to evaluate the accuracy of different tests for the screening of schistosomiasis in African migrants, in a non endemic setting.Methodology/Principal findingsA retrospective study was conducted on 373 patients screened at the Centre for Tropical Diseases (CTD) in Negrar, Verona, Italy. Biological samples were tested with: stool/urine microscopy, Circulating Cathodic Antigen (CCA) dipstick test, ELISA, Western blot, immune-chromatographic test (ICT). Test accuracy and predictive values of the immunological tests were assessed primarily on the basis of the results of microscopy (primary reference standard): ICT and WB resulted the test with highest sensitivity (94% and 92%, respectively), with a high NPV (98%). CCA showed the highest specificity (93%), but low sensitivity (48%). The analysis was conducted also using a composite reference standard, CRS (patients classified as infected in case of positive microscopy and/or at least 2 concordant positive immunological tests) and Latent Class Analysis (LCA). The latter two models demonstrated excellent agreement (Cohen's kappa: 0.92) for the classification of the results. In fact, they both confirmed ICT as the test with the highest sensitivity (96%) and NPV (97%), moreover PPV was reasonably good (78% and 72% according to CRS and LCA, respectively). ELISA resulted the most specific immunological test (over 99%). The ICT appears to be a suitable screening test, even when used alone.ConclusionsThe rapid test ICT was the most sensitive test, with the potential of being used as a single screening test for African migrants.