Epidemiology Section, Department of Production Animal Studies, University of Pretoria, Private Bag X04, Onderstepoort 0110 South Africa.
Vet Parasitol. 2011 Jan 10;175(1-2):155-9. doi: 10.1016/j.vetpar.2010.10.004. Epub 2010 Nov 13.
This study determined the prevalence of Cryptosporidium spp. oocysts in faecal samples from elephant (Loxodonta africana), buffalo (Syncerus caffer) and impala (Aepyceros melampus) in the Kruger National Park (KNP) and an adjacent game reserve in South Africa. Two of the study areas were in close proximity to rural communities on the western KNP boundary and the third study area was located in the centre of the KNP. Fresh stool samples (n=445) were collected and tested using an immunofluorescent antibody test (IFA) for Cryptosporidium parvum. A total of 278 of these were randomly selected (approximately 90 samples per wildlife species) and tested with the modified Ziehl Neelsen staining technique (ZN) for Cryptosporidium spp. The prevalence of Cryptosporidium spp. was highest in elephants (25.8% [95% confidence interval: 17.3, 35.9]), compared to buffalo (5.5% [1.8, 12.4]) and impala (4.3% [1.2, 10.5]). C. parvum showed similar patterns, being most prevalent in elephants (4.2% [1.5, 8.8]), compared to buffalo (1.4% [0.2, 5.1]) and impala (1.9% [0.4, 5.3]). 29 samples, including ZN positive and IFA positive samples, were retested using a real time PCR (rtPCR) technique. Of the 28 ZN-positive samples, 14 (50%) were positive with rtPCR and of the 9 IFA-positive samples 6 (67%) were confirmed positive by rtPCR. The prevalence of Cryptosporidium oocysts was significantly higher in both of the two study areas adjacent to the western KNP boundary compared to the area in the centre of the KNP (OR=3.2 [1.2, 9.0]; P=0.024). Our study demonstrates for the first time the presence of Cryptosporidium spp. in wildlife in South Africa. The transmission of this parasite between wildlife, domestic animals and humans is a plausible hypothesis and represents a potential risk for immunodeficient human populations.
本研究旨在确定克鲁格国家公园（KNP）和南非毗邻的一个野生动物保护区内的大象（Loxodonta africana）、非洲水牛（Syncerus caffer）和大羚羊（Aepyceros melampus）粪便样本中隐孢子虫属卵囊的流行率。研究的两个区域与 KNP 西部边界的农村社区非常接近，第三个区域位于 KNP 的中心。采集新鲜粪便样本（n=445），并用免疫荧光抗体试验（IFA）检测隐孢子虫小隐孢子虫。其中 278 个样本随机选择（每个野生动物物种约 90 个样本），并用改良的齐尔-尼尔森染色技术（ZN）检测隐孢子虫属。隐孢子虫属的流行率在大象中最高（25.8% [95%置信区间：17.3, 35.9]），其次是非洲水牛（5.5% [1.8, 12.4]）和大羚羊（4.3% [1.2, 10.5]）。小隐孢子虫的流行模式相似，在大象中最为普遍（4.2% [1.5, 8.8]），其次是非洲水牛（1.4% [0.2, 5.1]）和大羚羊（1.9% [0.4, 5.3]）。29 个样本，包括 ZN 阳性和 IFA 阳性样本，使用实时 PCR（rtPCR）技术进行了重新检测。在 28 个 ZN 阳性样本中，有 14 个（50%）用 rtPCR 检测为阳性，在 9 个 IFA 阳性样本中，有 6 个（67%）经 rtPCR 证实为阳性。与 KNP 中心区域相比，与 KNP 西部边界相邻的两个研究区域中隐孢子虫卵囊的流行率显著更高（OR=3.2 [1.2, 9.0]；P=0.024）。本研究首次证明了南非野生动物中存在隐孢子虫属。这种寄生虫在野生动物、家畜和人类之间的传播是一种合理的假设，代表了免疫功能低下的人类群体的潜在风险。
