Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, C.P. 486, Belo Horizonte, CEP 30.270-901, Minas Gerais, Brazil.
Vet Parasitol. 2010 May 11;169(3-4):320-6. doi: 10.1016/j.vetpar.2009.12.041. Epub 2010 Jan 7.
The aim of this study was to assess the epidemiological situation of bovine trypanosomiasis caused by Trypanosoma vivax in a dairy cattle herd from Igarapé, Minas Gerais state, Brazil. The herd was monitored from September 2007 to February 2009 by sampling blood for determination of packed cell volume (PCV), microhaematocrit centrifugation test of parasitaemia (MHCT), serology (IFA), morphological identification of T. vivax and molecular diagnosis by polymerase chain reaction (PCR). During all the experimental period, 25 animals were MHCT and PCR positive, considering that in each sample collection a mean of 70 animals was evaluated. The morphometric characteristics of trypomastigote forms confirmed the infection by T. vivax. The seroprevalence ranged from 7.4% in September 2007 to 48% in February 2009, and the highest incidence observed could be correlated with an increased population of Stomoxys calcitrans flies in that region. Anaemia was the most important change found in infected animals, which showed lower averages of PCV than parasitologically negative animals (p<0.0001). Infected individuals showed lower averages of PCV than parasitologically negative animals (p<0.0001), indicating higher anaemia in the former compared with the latter group.
本研究旨在评估巴西米纳斯吉拉斯州伊加拉佩一个奶牛场由布氏锥虫引起的牛锥虫病的流行情况。该牛场于 2007 年 9 月至 2009 年 2 月期间通过采集血液样本进行评估，包括红细胞压积（PCV）、微血球比容离心试验（MHCT）、寄生虫血症的间接免疫荧光分析（IFA）、布氏锥虫形态学鉴定和聚合酶链反应（PCR）分子诊断。在整个实验期间，25 头动物 MHCT 和 PCR 阳性，考虑到每次采样评估平均有 70 头动物。锥虫形态学特征证实了布氏锥虫的感染。血清阳性率从 2007 年 9 月的 7.4%到 2009 年 2 月的 48%不等，观察到的最高发病率可能与该地区斑虻数量的增加有关。贫血是感染动物最主要的变化，其 PCV 平均值低于寄生虫学阴性动物（p<0.0001）。感染个体的 PCV 平均值低于寄生虫学阴性动物（p<0.0001），表明前者比后者的贫血程度更高。
