Desquesnes Marc, Bossard Géraldine, Thévenon Sophie, Patrel Delphine, Ravel Sophie, Pavlovic Djamila, Herder Stéphane, Patout Olivier, Lepetitcolin Elisabeth, Hollzmuller Philippe, Berthier David, Jacquiet Philippe, Cuny Gérard
Département Systèmes Biologiques , UMR177-Trypanosomes, Montpellier F-34000, France.
Vet Parasitol. 2009 Jun 10;162(3-4):214-20. doi: 10.1016/j.vetpar.2009.03.033. Epub 2009 Mar 27.
An outbreak of trypanosomosis was observed for the first time in metropolitan France in October 2006, when five camels were proved to be infected by Trypanosoma evansi using parasitological methods. The parasite was isolated and used to produce a soluble antigen for antibody-enzyme linked immunosorbent assay (ELISA) in a protocol derived from a method previously developed for sheep and humans but using protein A conjugate. The animals were treated on three instances, alternatively with melarsomine hydrochloride and quinapyramine and followed up on a monthly basis for 2 years with various diagnostic techniques including parasitological, serological and DNA-based methods. Initially, five animals were detected as being positive using ELISA with 83.3% concordance to parasitological tests. Immediately after the first treatment, parasites and DNA disappeared in all animals; antibody levels decreased regularly until ELISA became negative 3-4 months later. Ten months after the first treatment, parasites and antibodies were detected again in one of the camels previously found to be infected. A retrospective study indicated that the weight of this animal had been underestimated; consequently, it had received underdosages of both trypanocides. However, since hypotheses of re-infection or relapse could not be fully substantiated, it is not known whether the ELISA results for this animal were true- or false-negative over a 7-month period. The study confirmed the value of this ELISA using protein A conjugate to detect antibodies directed against T. evansi in camels and the need to use several diagnostic techniques to optimize detection of infected animals. A warning is raised on surra, a potentially emerging disease in Europe.
2006年10月，在法国本土首次观察到锥虫病疫情，当时通过寄生虫学方法证实有5峰骆驼感染了伊氏锥虫。分离出该寄生虫，并按照先前为绵羊和人类开发的一种方法，但使用蛋白A缀合物，制备了一种可溶性抗原用于抗体酶联免疫吸附测定（ELISA）。这些动物接受了3次治疗，交替使用盐酸美拉胂醇和喹吖因，并采用包括寄生虫学、血清学和基于DNA的方法在内的各种诊断技术进行了为期2年的每月随访。最初，使用ELISA检测到5只动物呈阳性，与寄生虫学检测的一致性为83.3%。首次治疗后，所有动物体内的寄生虫和DNA立即消失；抗体水平持续下降，直到3 - 4个月后ELISA检测呈阴性。首次治疗10个月后，在先前发现感染的1峰骆驼中再次检测到寄生虫和抗体。一项回顾性研究表明，这峰骆驼的体重被低估了；因此，两种锥虫杀灭剂的用药剂量不足。然而，由于再感染或复发的假设无法得到充分证实，所以不清楚这峰骆驼在7个月期间的ELISA结果是真阴性还是假阴性。该研究证实了使用蛋白A缀合物的这种ELISA在检测骆驼体内针对伊氏锥虫抗体方面的价值，以及使用多种诊断技术以优化感染动物检测的必要性。同时对苏拉病发出了警告，这是一种在欧洲可能出现的疾病。
