Presence of Giardia cysts and Cryptosporidium oocysts in drinking water supplies in northern Spain
Presence of Giardia cysts and Cryptosporidium oocysts in drinking water supplies in northern Spain
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DOI：
10.1111/j.1365-2672.2006.03193.x
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发表时间：
2007-03-01
影响因子：
4
通讯作者：
Ocio, J. A.
中科院分区：
文献类型：
--
作者：
Carmena, D.;Aguinagalde, X.;Ocio, J. A.
目的：了解西班牙北部Alava省地表水中隐孢子虫和贾第鞭毛虫的流行情况，并探讨这两种致病性原生动物的存在与微生物学、理化和大气参数之间的关系。方法与结果：对284份饮用水和娱乐用水进行分析。在63.5%的河流样本、33.3%的水库样本、15.4%和22.6%的常规和小型水处理设施原水样本、30.8%的小型处理设施处理过的水以及26.8%的仅进行氯化处理的城市自来水中发现隐孢子虫卵囊。在92.3%的河流样本、55.5%的水库样本、常规水处理设施和小型水处理设施的原水样本（分别为26.9%和45.2%）、小型处理设施的处理过的水（19.2%）和仅进行氯化处理的城市的自来水（26.8%）中发现了贾第鞭毛虫囊肿。隐孢子虫和贾第鞭毛虫的检出率与样品浊度呈显著的Pearson相关（P < 0.01），与总大肠菌群和大肠杆菌的检出率呈显著相关。秋季隐孢子虫检出率显著高于春季和冬季（P < 0.05）。贾第鞭毛虫的季节分布没有显著差异。降雨与隐孢子虫卵囊的存在存在中度关联（r = 0.52）。结论：在西班牙北部阿拉瓦省供人类食用的地表水中，隐孢子虫和贾第鞭毛虫的浓度持续升高。研究的意义和影响：仅以快速过滤和/或氯化为基础的水处理往往不能令人满意地提供安全饮用水，由于水传播疾病爆发的风险，这种情况对受影响人口构成了一个重要的公共卫生问题。
Aims: To evaluate the prevalence of Cryptosporidium and Giardia in surface water supplies from the province of Alava, northern Spain, and to investigate possible associations among the presence of these pathogenic protozoa with microbiological, physicochemical and atmospheric parameters.Methods and results: A total of 284 samples of drinking and recreational water supplies were analysed. Cryptosporidium oocysts were found in 63.5% of river samples, 33.3% of reservoirs samples, 15.4% and 22.6% of raw water samples from conventional and small water treatment facilities (respectively), 30.8% of treated water from small treatment facilities, and 26.8% of tap water from municipalities with chlorination treatment only. Giardia cysts were found in 92.3% of river samples, 55.5% of reservoirs samples, 26.9% and 45.2% of raw water samples from conventional and small water treatment facilities (respectively), 19.2% of treated water from small treatment facilities, and 26.8% of tap water from municipalities with chlorination treatment only. The presence of Cryptosporidium and Giardia had significant Pearson's correlation coefficients (P < 0.01) with the turbidity levels of the samples, and a number of significant associations were also found with the count levels for total coliforms and Escherichia coli. The samples were positive for Cryptosporidium significantly (P < 0.05) more frequently during the autumn season than during the spring and winter seasons. No significant differences were found in the seasonal pattern of Giardia. A moderate association (r = 0.52) was found between rainfall and the presence of Cryptosporidium oocysts.Conclusions: Cryptosporidium and Giardia are consistently found at elevated concentrations in surface waters for human consumption from the province of Alava, northern Spain. Significance and Impact of the Study: Water treatments based on rapid filtration process and/or chlorination only are often unsatisfactory to provide safe drinking water, a situation that represents an important public health problem for the affected population because of the risk of waterborne outbreaks.