Theileria parasites commonly infect African wild artiodactyls. In rare roan (Hippotragus equinus) and sable (H. niger) antelopes, Theileria sp. (sable)-associated calf mortalities constrain breeding programs. The pathogenicity of most leukocyte-transforming Theileria spp. originates in their invasion of and multiplication in various mononuclear leukocytes, the transformation of both infected and uninfected leukocytes, and their infiltration of multiple organs. Understanding the pathogenesis of theileriosis can be improved by the use of immunohistochemistry (IHC) to identify the localization of the parasites in tissue sections. Our aim was to develop a reproducible IHC assay to detect leukocyte-associated Theileria parasites in formalin-fixed, paraffin-embedded roan and sable tissues. Polyclonal antibodies were purified from the sera of 5 roans from an area endemic for Theileria sp. (sable) and tested for IHC reactivity in 55 infected and 39 control roan and sable antelopes, and for antigen and species cross-reactivity in an additional 58 cases. The 3 strongest antibodies consistently detected intraleukocytic theilerial antigens in known positive cases in roan and sable antelopes, and also detected other Theileria spp. in non-hippotraginid wild artiodactyl tissues. The antibodies did not cross-react with other apicomplexan protozoa, with the exception of Cryptosporidium. Given that PCR on its own cannot determine the significance of theilerial infection in wild ruminants, IHC is a useful laboratory test with which to confirm the diagnosis in these species.

泰勒虫寄生虫通常感染非洲野生偶蹄动物。在稀有的马羚 ( Hippotragus equinus ) 和黑貂 ( H. niger ) 羚羊中，泰勒菌属。（紫貂）相关的小牛死亡率限制了育种计划。大多数白细胞转化泰勒菌属的致病性。起源于它们对各种单核白细胞的侵袭和增殖，感染和未感染的白细胞的转化，以及它们对多个器官的浸润。通过使用免疫组织化学 (IHC) 来确定寄生虫在组织切片中的定位，可以提高对泰勒虫病发病机制的了解。我们的目标是开发一种可重复的 IHC 检测方法来检测白细胞相关福尔马林固定、石蜡包埋的绒毛和紫貂组织中的泰勒虫寄生虫。多克隆抗体是从泰勒虫流行地区的 5 只动物的血清中纯化出来的。（紫貂）并在 55 只受感染的羚羊和 39 只对照马羚和黑貂羚羊中测试了 IHC 反应性，并在另外 58 例中测试了抗原和物种交叉反应性。3 种最强的抗体在已知的马羚和黑貂羚羊的阳性病例中始终检测到白细胞内泰勒虫抗原，并且还检测到其他泰勒虫属。在非河马属野生偶蹄动物组织中。抗体不与其他顶复门原生动物发生交叉反应，隐孢子虫除外. 鉴于 PCR 本身无法确定野生反刍动物感染的重要性，IHC 是一种有用的实验室测试，可用于确认这些物种的诊断。