Zicker F, Smith P G, Luquetti A O, Oliveira O S
Department of Community Health, Universidade Federal de Goiás, Golánia, Brazil.
Bull World Health Organ. 1990;68(4):465-71.
Methods used to diagnose Trypanosoma cruzi infection differ in their ability to discriminate between sera from infected and uninfected individuals. We compared the results of an immunofluorescence (IF) test, a haemagglutination (HA) test, and an enzyme-linked immunosorbent assay (ELISA) for the diagnosis of T. cruzi infections in a large population-based survey in central Brazil using blood eluates from filter-paper and venous blood samples. The sensitivities of the tests on eluates, compared with results on serum samples, were low: ELISA (78.1%), IF (69.2%) and HA (64.6%). The level of agreement between the tests on eluates was very poor, with the best co-positivity for IF and ELISA. Both the positive and negative predictive values of the three tests on eluates were similar (around 96%) to those for sera. Higher co-positivity values were obtained for the three tests on sera. The implications of these results are discussed in relation to blood screening, routine medical practice, sero-epidemiological surveys, and the follow-up of patients admitted to therapeutic trials.
用于诊断克氏锥虫感染的方法在区分感染个体和未感染个体血清的能力上存在差异。在巴西中部一项基于人群的大型调查中，我们使用滤纸血洗脱液和静脉血样本，比较了免疫荧光（IF）试验、血凝（HA）试验和酶联免疫吸附测定（ELISA）诊断克氏锥虫感染的结果。与血清样本结果相比，这些试验对洗脱液检测的灵敏度较低：ELISA（78.1%）、IF（69.2%）和HA（64.6%）。洗脱液检测结果之间的一致性很差，IF和ELISA的共同阳性率最高。三种洗脱液检测的阳性预测值和阴性预测值与血清检测的结果相似（约96%）。血清的三种检测获得了更高的共同阳性率值。结合血液筛查、常规医疗实践、血清流行病学调查以及接受治疗试验患者的随访，对这些结果的影响进行了讨论。
