Post-Graduate Program in Pathology, School of Medicine, Federal University of Ceará, Fortaleza, Brazil.
Laboratory of Parasitology and Mollusc Biology, Department of Clinical Analysis and Toxicology, Federal University of Ceará, Fortaleza, Brazil.
Parasitology. 2021 Apr;148(4):420-426. doi: 10.1017/S0031182020002164. Epub 2020 Nov 16.
This study aimed to evaluate the performance of the point-of-care circulating cathodic antigen (POC-CCA) test in a highly endemic area in Brazil, comparing it to the Kato-Katz (KK) technique for sensitivity, specificity and the intensity of the reaction of the test in relation to the parasitic load. The community in Sergipe, Brazil, participated in the study, providing three stool samples, one of urine (POC-CCA) and fingers tick blood sample was tested by enzyme-linked immunosorbent assay (ELISA). Sensitivity, specificity, positive predictive value, negative predictive value, accuracy, kappa coefficient and Spearman's correlation were calculated for the POC-CCA test using the KK as the reference. The prevalence of schistosomiasis by KK testing was 48.82%; POC-CCA (t+) 66.14%; POC-CCA (t-) 45.24%. ELISA results showed 100% agreement in individuals with high and moderate eggs per gram (EPG). POC-CCA presented good diagnostic performance in individuals with medium and high EPG, but there were a high number of false negatives in individuals with low intensity infections. As observed, POC-CCA-filter test improves accuracy and sensitivity compared to a conventional test.
本研究旨在评估即时检测循环阴离子抗原(POC-CCA)试验在巴西高度流行地区的性能,将其与加藤氏厚涂片法(KK)进行比较,以评估其敏感性、特异性以及与寄生虫负荷相关的反应强度。巴西塞尔希培州的社区参与了这项研究,提供了三份粪便样本、一份尿液样本(POC-CCA)和手指采血样本,通过酶联免疫吸附试验(ELISA)进行检测。使用 KK 作为参考,计算了 POC-CCA 试验的敏感性、特异性、阳性预测值、阴性预测值、准确性、kappa 系数和斯皮尔曼相关性。KK 检测的血吸虫病流行率为 48.82%;POC-CCA(t+)为 66.14%;POC-CCA(t-)为 45.24%。ELISA 结果显示,在高和中度每克粪便虫卵数(EPG)的个体中,结果具有 100%的一致性。POC-CCA 在中、高 EPG 个体中具有良好的诊断性能,但在低强度感染个体中存在大量假阴性。结果表明,与传统检测方法相比,POC-CCA 滤器检测提高了准确性和敏感性。