Identifying host sources, human health risk and indicators of Cryptosporidium and Giardia in a Canadian watershed influenced by urban and rural activities
Identifying host sources, human health risk and indicators of Cryptosporidium and Giardia in a Canadian watershed influenced by urban and rural activities
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DOI：
10.2166/wh.2012.131
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发表时间：
2012-01-01
影响因子：
2.3
通讯作者：
Huck, Peter M.
中科院分区：
文献类型：
--
作者：
Van Dyke, Michele I.;Ong, Corinne S. L.;Huck, Peter M.
隐孢子虫和贾第鞭毛虫的特点是在加拿大安大略南部的一个分水岭，超过2 1/2年的时间。每两周收集一次河流样本，主要是在市政饮用水处理厂取水口附近。隐孢子虫和贾第鞭毛虫是经常检测到的总发生率分别为88%和97%。贾第鞭毛虫浓度高于隐孢子虫，中位数值分别为80个囊100 L-1和12个卵囊100 L-1。虽然病原体很少表现出显着的关系，粪便或水质指标，这项研究确定，隐孢子虫，而不是贾第虫，显着相关的大肠杆菌，浊度和河流流量。有两种类型的原生动物之间没有相关性，只有贾第鞭毛虫表现出较高的浓度在冷水温度的季节性趋势。所有样本的隐孢子虫基因分型发现，农场动物和野生动物是分水岭卵囊的重要贡献者，并且隐孢子虫菌株/基因型对人类感染的中高风险（C. hominis，C. parvum和C.在16%的样本中检测到了泛素。这项研究能够确定隐孢子虫宿主来源和人类健康风险，并确定隐孢子虫和贾第鞭毛虫发生在流域之间的差异。
Cryptosporidium and Giardia were characterized in a watershed in southern Ontario, Canada, over a 2 1/2 year period. River samples were collected every two weeks, primarily near a municipal drinking water treatment plant intake. Cryptosporidium and Giardia were frequently detected with an overall occurrence rate of 88 and 97%, respectively. Giardia concentrations were higher than Cryptosporidium, with median values of 80 cysts 100 L-1 and 12 oocysts 100 L-1, respectively. Although pathogens rarely show a significant relationship with fecal or water quality indicators, this study determined that Cryptosporidium, but not Giardia, was significantly correlated with Escherichia coli, turbidity and river flow. There was no correlation between the two types of protozoa, and only Giardia showed a seasonal trend with higher concentrations at cold water temperatures. Cryptosporidium genotyping of all samples found that farm animals and wildlife were an important contributor of oocysts in the watershed, and that Cryptosporidium strains/genotypes of medium to high risk for human infection (C. hominis, C. parvum and C. ubiquitum) were detected in 16% of samples. This study was able to identify Cryptosporidium host sources and human health risk, and to identify differences between Cryptosporidium and Giardia occurrence in the watershed.