Murray M, Trail J C, D'Ieteren G D
Department of Veterinary Medicine, University of Glasgow Veterinary School, Bearsden, Scotland, United Kingdom.
Rev Sci Tech. 1990 Jun;9(2):369-86. doi: 10.20506/rst.9.2.506.
Tsetse-transmitted trypanosomiasis is one of the major constraints on the expansion of the livestock and agricultural industries in Africa. The disease affects animals and man, with direct and indirect losses estimated in billions of dollars annually. Because of the phenomenon of antigenic variation, no vaccine is available. Current prophylactic efforts must rely on tsetse control by the use of insecticides and on trypanocidal drugs. However, recent advances in our knowledge of tsetse and trypanosome biology are offering hope for alternative methods of trapping tsetse, new drugs and even vaccination. Possibly of even greater significance is the increasing sense that Africa herself might be able to contribute to the resolution of this problem. Over a period of several thousand years, she has generated cattle, such as the taurine N'Dama and West African Shorthorn breeds of West and Central Africa, that are now known to possess a significant degree of innate resistance to trypanosomiasis and several other important infectious diseases. These cattle are extremely well adapted to the environment and are now recognised as having considerable production potential. The ability to resist the development of anaemia in the face of infection, as assessed by packed red cell volume percent (PCV), has been shown to be correlated with the capacity to be productive, thereby identifying regulation of PCV as a key trait of trypanotolerance. Thus, an estimate of the ability of an infected animal to maintain PCV, following either experimental or field infection, could be used as a method for identifying trypanotolerant individuals. This could provide a means of estimating trypanotolerance heritability, thereby permitting rational breeding programmes to be instituted. Africa may thus provide the answer.
采采蝇传播的锥虫病是非洲畜牧业和农业发展的主要制约因素之一。这种疾病会影响动物和人类，每年造成的直接和间接损失估计达数十亿美元。由于抗原变异现象，目前尚无可用疫苗。当前的预防措施必须依靠使用杀虫剂控制采采蝇以及使用杀锥虫药物。然而，我们对采采蝇和锥虫生物学知识的最新进展为诱捕采采蝇的替代方法、新药甚至疫苗带来了希望。或许更具意义的是，人们越来越意识到非洲自身可能有能力为解决这一问题做出贡献。在几千年的时间里，非洲培育出了一些牛种，比如西非和中非的牛属恩达马牛以及西非短角牛，现在已知这些牛对锥虫病和其他几种重要传染病具有显著程度的先天抵抗力。这些牛对环境的适应性极强，如今被认为具有相当大的生产潜力。通过红细胞压积百分比（PCV）评估，抵抗感染时贫血发展的能力已被证明与生产能力相关，从而确定PCV的调节是锥虫耐受性的关键特征。因此，在实验感染或野外感染后，对感染动物维持PCV能力的估计可作为识别锥虫耐受个体的一种方法。这可以提供一种估计锥虫耐受性遗传力的手段，从而能够制定合理的育种计划。非洲或许就能提供解决方案。
