Laboratoire de Parasitologie, Ecole Nationale Vétérinaire, BP 87 614, 31 076 Toulouse Cedex 03, France.
Vet Parasitol. 2011 Apr 19;177(1-2):20-7. doi: 10.1016/j.vetpar.2010.11.030. Epub 2010 Nov 25.
Bovine besnoitiosis, caused by the cyst-forming apicomplexan Besnoitia besnoiti, is commonly reported in some restricted regions of South-Western Europe, and in larger regions of Africa and Asia. This infection is thought to be transmitted by blood feeding insects and is responsible for major economic losses in cattle production. A recent emergence in Europe, notified in the Centre of France, Spain and Germany, has attracted more attention to this disease. Clinical signs could appear in some animals; however, many infected cattle remain asymptomatic or show scleral-conjunctival cysts (SCC) only. Recent development of serological methods allows carrying out seroepidemiological field studies. In this respect, a long-term investigation was performed in a dairy cattle farm localized in an enzootic area of besnoitiosis of South-western France between March 2008 and May 2009. The objective was to estimate the seasonal pattern of B. besnoiti infections based on the presence of SCC and serology (ELISA and Western blot). In parallel, an entomological survey was conducted to describe population dynamics of Stomoxys calcitrans and Tabanidae species. The seroprevalence determined by Western blot in a cohort of 57 animals continuously present during the whole survey increased from 30% in March 2008 to 89.5% in May 2009 and was always higher than the prevalence based on clinically assessed SCC. New positive B. besnoitia seroconversions occurred throughout the year with the highest number in spring. In addition, many seroconversions were reported in the two months before turn-out and could be associated with a high indoors activity of S. calcitrans during this period.
牛贝氏贝虫病由形成包囊的顶复门原虫贝氏贝虫引起，常见于欧洲西南部的一些限制区域，以及非洲和亚洲的更大区域。这种感染被认为是通过吸血昆虫传播的，是导致牛生产重大经济损失的原因。最近在欧洲出现的一种感染，在法国中心、西班牙和德国都有报道，引起了人们对这种疾病的更多关注。一些动物可能会出现临床症状；然而，许多受感染的牛仍无症状或仅出现巩膜-结膜囊肿（SCC）。最近血清学方法的发展允许进行血清流行病学现场研究。在这方面，在法国西南部贝氏贝虫病流行地区的一个奶牛场进行了一项长期调查，时间为 2008 年 3 月至 2009 年 5 月。目的是根据 SCC 和血清学（ELISA 和 Western blot）的存在来估计 B. besnoiti 感染的季节性模式。同时，还进行了昆虫学调查，以描述厩螫蝇和虻科昆虫的种群动态。通过 Western blot 在一个连续存在于整个调查期间的 57 头动物的队列中确定的血清阳性率从 2008 年 3 月的 30%增加到 2009 年 5 月的 89.5%，并且始终高于基于临床评估 SCC 的流行率。全年都有新的 B. besnoitia 血清学转化发生，春季最多。此外，在出牧前的两个月报告了许多血清学转化，这可能与这段时间内厩螫蝇的室内活动增加有关。
