Trypanosoma evansi (T. evansi) is a hemoflagellate parasite that affects a broad range of mammalian hosts and that causes a disease called surra. Diagnosis of surra based on clinical symptoms alone is inaccurate. Therefore, a variety of serological and molecular diagnostic tests are used to assist in the detection of T. evansi infections. The aim of this study was to compare the diagnostic performance of four serological tests (CATT/T.evansi, immune trypanolysis, ELISA with purified variant surface glycoprotein RoTat 1.2 and with whole cell lysate) and two molecular PCR tests targeting sequences within the ribosomal genes locus (ITS1 TD PCR and 18S qPCR). Tests were carried out on blood samples from 161 dromedary camels, 93 horses, 129 goats, 168 sheep, 127 bovines and 76 dogs. Latent class analysis was carried out to calculate the sensitivity and specificity of each diagnostic test. Cohen's Kappa test was used to assess the concordance between the different diagnostic tests. Overall positivity rates observed with the serological tests were as follows: 3.1 % with CATT/T.evansi, 4.9 % with ELISA/RoTat 1.2, 3.4 % with ELISA/whole lysate and 2.0 % with immune trypanolysis (TL). Among the 754 samples tested with the molecular tests, 1.7 % were positive with 18S qPCR and 1.3 % with ITS1 TD PCR. Cohen's Kappa test showed agreement ranging from fair to substantial (k = 0.2-0.8) between serological diagnostic tests. However, it showed a perfect agreement (k = 0.868) between molecular diagnostic tests. Latent class analysis showed that all serological tests were 100 % sensitive, in contrast to the molecular tests with 47 % sensitivity. All tests, though, were highly specific (≥ 97 %). Given the persistence of circulating antibodies after cure, detectable by serological tests, it is recommend combining a serological and a molecular diagnostic test for accurate diagnosis of infection with T. evansi in domestic animals.

中文翻译：

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血清学和分子学检测法比较南阿尔及利亚Ghardaïa区家畜中的伊文锥虫的能力。

埃文氏锥虫（T. evansi）是鞭毛虫的寄生虫，会影响多种哺乳动物宿主，并导致一种称为surra的疾病。仅根据临床症状对surra的诊断是不准确的。因此，多种血清学和分子诊断测试可用于协助检测伊文氏锥虫感染。这项研究的目的是比较四种血清学检测（CATT / T.evvan，免疫锥虫溶解，具有纯化的变体表面糖蛋白RoTat 1.2的ELISA和全细胞裂解液）和两种针对核糖体基因序列的分子PCR检测的诊断性能位点（ITS1 TD PCR和18S qPCR）。对来自161只单峰骆驼，93匹马，129只山羊，168只绵羊，127头牛和76条狗的血液样本进行了测试。进行潜在类别分析以计算每个诊断测试的敏感性和特异性。Cohen的Kappa检验用于评估不同诊断检验之间的一致性。血清学测试观察到的总体阳性率如下：CATT / T.van的3.1％，ELISA / RoTat 1.2的4.9％，ELISA /全裂解液的3.4％，免疫锥虫病（TL）的2.0％。在通过分子测试测试的754个样本中，使用18S qPCR的阳性率为1.7％，使用ITS1 TD PCR的阳性率为1.3％。科恩的Kappa试验显示，血清学诊断试验之间的一致性从中等到显着（k = 0.2-0.8）。但是，它在分子诊断测试之间显示出完美的一致性（k = 0.868）。潜在类别分析显示，所有血清学检查均100％敏感，与灵敏度为47％的分子测试相反。但是，所有测试都具有很高的特异性（≥97％）。鉴于治愈后循环抗体的持久性（可通过血清学检测法检测到），建议结合血清学和分子诊断检测法，以准确诊断家畜中的伊文氏杆菌感染。