Kaufmann J, Dwinger R H, Hallebeek A, van Dijk B, Pfister K
Department of Veterinary Parasitology, University of Berne, Switzerland.
Vet Parasitol. 1992 Jul;43(3-4):157-70. doi: 10.1016/0304-4017(92)90157-5.
The interactions between Trypanosoma congolense and Haemonchus contortus infections were studied in N'Dama calves. A total of 38 N'Dama bulls was divided into four groups and each group infected either with H. contortus 1 week after infection with T. congolense or with T. congolense 4 weeks after infection with H. contortus, or with either infection singly. Parasitological (faecal egg counts, parasitaemia), haematological (packed cell volume, white blood cell counts, albumin) and clinical parameters (body weight change, mortality rate) were compared among the various groups. The results showed a reduced prepatent period and a markedly increased pathogenicity of H. contortus infections in animals with a concurrent T. congolense infection. The most harmful combination was a H. contortus infection 1 week after the T. congolense infection which resulted in a progressive and severe anaemia, accompanied by hypoalbuminaemia, increased weight loss and high mortality. The anaemia induced by dual infections showed a low responsiveness to chemotherapy and in several cases supportive treatment did not help recovery. The results also showed that animals with a concurrent T. congolense and H. contortus infection ran a higher risk of succumbing during the infection, and also during 10 weeks following treatment. Although infections with T. congolense alone produced no clinical signs, they were found to significantly reduce the ability of infected animals to mount a normal response to a subsequent H. contortus infection. It was concluded that the increased H. contortus egg excretion observed in animals infected with both parasites might significantly increase the risk of nematode infections and that the reduced prepatent period might necessitate more frequent anthelmintic treatments. These interactions should, therefore, be considered wherever attempts are made to control these two diseases.
在恩达马小牛中研究了刚果锥虫与捻转血矛线虫感染之间的相互作用。总共38头恩达马公牛被分为四组，每组在感染刚果锥虫1周后感染捻转血矛线虫，或在感染捻转血矛线虫4周后感染刚果锥虫，或单独感染其中一种寄生虫。比较了各组之间的寄生虫学指标（粪便虫卵计数、虫血症）、血液学指标（红细胞压积、白细胞计数、白蛋白）和临床参数（体重变化、死亡率）。结果显示，同时感染刚果锥虫的动物中，捻转血矛线虫感染的潜伏期缩短，致病性明显增加。最有害的组合是在感染刚果锥虫1周后感染捻转血矛线虫，这导致进行性严重贫血，伴有低白蛋白血症、体重减轻增加和高死亡率。双重感染引起的贫血对化疗反应较低，在一些情况下，支持性治疗无助于恢复。结果还表明，同时感染刚果锥虫和捻转血矛线虫的动物在感染期间以及治疗后的10周内死亡风险更高。虽然单独感染刚果锥虫没有产生临床症状，但发现它们会显著降低感染动物对随后捻转血矛线虫感染产生正常反应的能力。得出的结论是，在感染两种寄生虫的动物中观察到的捻转血矛线虫卵排泄增加可能会显著增加线虫感染的风险，潜伏期缩短可能需要更频繁地进行驱虫治疗。因此，无论在何处尝试控制这两种疾病，都应考虑这些相互作用。
