Downstream Industry Development Division, Department of Veterinary Services Malaysia, Lot 4G1, Presint 4, Wisma Tani, 62630 Putrajaya, Malaysia.
Exp Parasitol. 2011 Feb;127(2):534-8. doi: 10.1016/j.exppara.2010.10.015. Epub 2010 Nov 2.
A cross-sectional study was carried out to identify species and determine the prevalence of Cryptosporidium sp. shedding in pre-weaned and post-weaned dairy calves and to identify management factors that may be contributing to disease. A total of 240 calf faecal samples were collected from 16 farms in two districts in Johor, Malaysia, and screened by PCR. The overall Cryptosporidium prevalence was 27.1%. The prevalence of Cryptosporidium species in pre-weaned calves was 32.4% for C. parvum, 26.5% for C. bovis, followed by C. andersoni (20.6%), C. ryanae (11.8%) and mixed sp. (8.8%). The prevalence of Cryptosporidium species in post-weaned calves was 35% for C. bovis followed by C. andersoni and C. ryanae (30% each) and mixed sp. (5%). Subtyping analysis of 8 of the 11 C. parvum isolates at the gp60 locus identified five isolates as IIdA15G1, one as IIa18A3R1 and two isolates as IIa17G2R1. Management factors that increased the risk of Cryptosporidium infection included having other cattle farms close by, feeding calves with saleable milk, keeping pre-weaned calves in pens with slatted floors and keeping post-weaned calves in pens with a sand floor.
本研究采用横断面调查方法，旨在鉴定马来西亚柔佛州两个地区 16 个牧场的未断奶和断奶后犊牛的隐孢子虫种类，并确定可能导致疾病的管理因素。共采集 240 份犊牛粪便样本，通过 PCR 进行筛查。隐孢子虫总流行率为 27.1%。未断奶犊牛的隐孢子虫流行率分别为：小隐孢子虫 32.4%、牛隐孢子虫 26.5%、随后为安氏隐孢子虫 20.6%、瑞安隐孢子虫 11.8%和混合种 8.8%。断奶后犊牛的隐孢子虫流行率分别为：牛隐孢子虫 35%、随后为安氏隐孢子虫和瑞安隐孢子虫（各 30%）和混合种（5%）。对 11 个小隐孢子虫分离株中的 8 个在 gp60 基因座进行的亚型分析，鉴定出 5 个分离株为 IIdA15G1，1 个为 IIa18A3R1，2 个为 IIa17G2R1。增加隐孢子虫感染风险的管理因素包括附近有其他牛场、用可销售牛奶喂养犊牛、将未断奶犊牛饲养在有漏缝地板的畜栏中和将断奶后犊牛饲养在沙土地板畜栏中。
