Kanyari P W
University of Nairobi, Department of Veterinary Pathology and Microbiology, Kabete, Kenya.
Vet Parasitol. 1993 Dec;51(1-2):137-41. doi: 10.1016/0304-4017(93)90204-z.
Studies on prevalence of coccidian oocysts and their infection levels (oocysts g-1, OPG) were carried out among various age groups of sheep and goats from different geographical locations in Kenya. Prevalent species of Eimeria were identified and levels of infection with strongyle eggs (eggs g-1, EPG) examined. A significant difference was found in the EPG levels between various farms but not in the OPG levels; this was attributed to the relative susceptibility of various preparasitic stages of helminths to adverse climatic conditions, especially desiccation, compared with coccidian oocysts. There was a negative correlation between OPG levels and the age of animals as a result of acquired immunity. Between OPG and EPG values there was a positive correlation which is in tandem with the role of contamination in the acquisition of both types of infection. Sheep were found to shed significantly more oocysts and helminth eggs than goats; this could be related to the differences in their mode of feeding, i.e. grazing and browsing respectively. Young age (under 1 year) and confinement were found to contribute to high prevalence of oocysts in faecal samples. In sheep, a total of ten species of Eimeria were identified, the most prevalent being E. ovina (43%) and E. ovinoidalis (16.5%). In goat samples, eight species were identified, the commonest being E. arloingi (37.5%) and E. ninakohlyakimovae (35.2%).
对肯尼亚不同地理位置的不同年龄组绵羊和山羊的球虫卵囊流行率及其感染水平（每克粪便中的卵囊数，OPG）进行了研究。鉴定了艾美耳球虫的流行种类，并检查了圆线虫卵的感染水平（每克粪便中的卵数，EPG）。发现不同农场之间的EPG水平存在显著差异，但OPG水平没有差异；这归因于与球虫卵囊相比，蠕虫不同寄生前期对不利气候条件，尤其是干燥的相对敏感性。由于获得性免疫，OPG水平与动物年龄之间存在负相关。OPG和EPG值之间存在正相关，这与两种感染的获得过程中污染所起的作用一致。发现绵羊排出的卵囊和蠕虫卵明显多于山羊；这可能与它们的采食方式差异有关，即分别为放牧和啃食。发现幼龄（1岁以下）和圈养会导致粪便样本中卵囊的高流行率。在绵羊中，共鉴定出10种艾美耳球虫，最常见的是卵形艾美耳球虫（43%）和类圆形艾美耳球虫（16.5%）。在山羊样本中，鉴定出8种，最常见的是阿氏艾美耳球虫（37.5%）和纳氏艾美耳球虫（35.2%）。
