Reid S A, Copeman D B
Western Australian Biomedical Research Institute, School of Veterinary and Biomedical Sciences, Murdoch University, South Street, Western Australia, 6150 Murdoch, Australia.
Prev Vet Med. 2003 Nov 12;61(3):195-208. doi: 10.1016/j.prevetmed.2003.07.004.
Trypanosoma evansi is exotic to Australia and Papua New Guinea (PNG). However, it might have been introduced to Papua (Indonesia); thus, there is a risk of it entering PNG and thence Australia. Because of logistical difficulties in PNG and northern Australia, surveillance for T. evansi must rely on serological tests. The accuracy of an Ab-ELISA using a detergent extract of T. evansi and three antigen fractions purified from the detergent extract using stepwise precipitation with saturated ammonium sulphate (AS) were compared. The ELISA using the AS 40-50% fraction had greater discriminatory power compared to the ELISA using the other antigen fractions. This ELISA then was compared with two commercial tests: the Card Agglutination Test for trypanosomiasis/T. evansi (CATT) and Suratex. CATT/T. evansi at 1/4 serum dilution has higher sensitivity and the ELISA has higher specificity. There is no likely benefit in combining antibody detection tests to improve the accuracy of diagnosis. Furthermore, the combination of Suratex (which was independent of the antibody tests) with the CATT or the ELISA did not improve the sensitivity. None of the tests was sufficiently sensitive to be used confidently to determine freedom from infection in animals imported into Australia from countries where T. evansi infection is endemic.
伊氏锥虫对澳大利亚和巴布亚新几内亚来说是外来物种。然而，它可能已传入巴布亚（印度尼西亚）；因此，存在传入巴布亚新几内亚并进而传入澳大利亚的风险。由于巴布亚新几内亚和澳大利亚北部存在后勤困难，对伊氏锥虫的监测必须依靠血清学检测。比较了一种使用伊氏锥虫去污剂提取物的抗体酶联免疫吸附测定（Ab - ELISA）以及使用饱和硫酸铵（AS）分步沉淀法从该去污剂提取物中纯化得到的三种抗原组分的Ab - ELISA的准确性。与使用其他抗原组分的ELISA相比，使用AS 40 - 50%组分的ELISA具有更强的鉴别能力。然后将这种ELISA与两种商业检测方法进行比较：锥虫病/伊氏锥虫卡片凝集试验（CATT）和Suratex。血清稀释度为1/4时的CATT/伊氏锥虫检测具有更高的灵敏度，而ELISA具有更高的特异性。联合抗体检测试验以提高诊断准确性可能并无益处。此外，将Suratex（与抗体检测无关）与CATT或ELISA联合使用并未提高灵敏度。没有一种检测方法足够灵敏，能够可靠地用于确定从伊氏锥虫感染流行国家进口到澳大利亚的动物是否未受感染。
