UK Cryptosporidium Reference Unit, Public Health Wales Microbiology, Singleton Hospital, Swansea, UK.
J Appl Microbiol. 2011 Sep;111(3):717-30. doi: 10.1111/j.1365-2672.2011.05068.x. Epub 2011 Jul 20.
Investigating the distribution and origin of Cryptosporidium species in a water catchment affected by destocking and restocking of livestock as a result of a foot and mouth disease epidemic.
Surface water, livestock and wildlife samples were screened for Cryptosporidium and oocysts characterised by sequencing SSU rRNA and COWP loci, and fragment analysis of ML1, ML2 and GP60 microsatellite loci. Oocyst concentrations in water samples (0-20.29 per 10 l) were related to rainfall events, amount of rainfall and topography. There was no detectable impact from catchment restocking. Cryptosporidium spp. found in water were indicative of livestock (Cryptosporidium andersoni and Cryptosporidium parvum) and wildlife (novel genotypes) sources. However, C. andersoni was not found in any animals sampled. Calf infections were age related; C. parvum was significantly more common in younger animals (<4 weeks old). Older calves shared Cryptosporidium bovis, Cryptosporidium ryanae and C. parvum. Wildlife shed C. parvum, Cryptosporidium ubiquitum, muskrat genotype II and deer genotype.
Several factors affect the occurrence of Cryptosporidium within a catchment. In addition to farmed and wild animal hosts, topography and rainfall patterns are particularly important.
These factors must be considered when undertaking risk-based water safety plans.
调查受口蹄疫影响而进行牲畜清群和补群的集水区中，隐孢子虫种的分布和来源。
对地表水、牲畜和野生动物样本进行隐孢子虫和卵囊筛查，方法是对 SSU rRNA 和 COWP 基因座进行测序，并对 ML1、ML2 和 GP60 微卫星基因座进行片段分析。水样中的卵囊浓度（0-20.29 个/10 升）与降雨事件、降雨量和地形有关。集水区补群没有可检测到的影响。在水中发现的隐孢子虫属指示了牲畜（隐孢子虫和小隐孢子虫）和野生动物（新型基因型）的来源。然而，在任何采样的动物中都没有发现隐孢子虫属。牛犊感染与年龄有关；<4 周龄的幼畜中更常见小隐孢子虫。年长的牛犊共同感染了隐孢子虫属牛种、隐孢子虫属 Ryan 种和小隐孢子虫。野生动物排出小隐孢子虫、隐孢子虫属 ubiquitum、麝香鼠基因型 II 和鹿基因型。
有几个因素会影响集水区中隐孢子虫的发生。除了饲养动物和野生动物宿主外，地形和降雨模式尤其重要。
在进行基于风险的水安全计划时，必须考虑这些因素。
