在渥太华（加拿大）地区的51个河流原水样本中，分别测定了隐孢子虫卵囊、贾第虫囊肿、粪便和总大肠菌群、粪便链球菌、气单胞菌属、铜绿假单胞菌、产气荚膜梭菌、藻类和大肠噬菌体的浓度。这项研究还检验了原生动物浓度与未经处理的地表水当前或潜在水质指标之间的相关性。本文还报告了两个水处理厂和一个污水处理厂中隐孢子虫卵囊和蓝氏贾第鞭毛虫囊的浓度。在未经处理的地表水样中观察到粪便链球菌和隐孢子虫卵囊之间以及贾第虫和体细胞大肠杆菌噬菌体和藻类之间存在显著相关性，但这种关系似乎是分水岭- 依靠的原生动物的存在与产气荚膜梭菌或任何其他指标之间没有显著相关性。包括40个参考文献、表格和图表。

Concentrations of Cryptosporidium oocysts, Giardia cysts, fecal and total coliforms, fecal streptococci, Aeromonas sp., Pseudomonas aeruginosa, Clostridium perfringens, algae, and coliphages were measured in each of 51 raw water samples from rivers in the Ottawa (Canada) region over three months. This study also examined correlations between the protozoa concentrations and current or potential indicators of water quality in raw surface water. The article also reports the concentrations of Cryptosporidium oocysts and Giardia lamblia cysts in two water treatment plants and in one wastewater plant. Significant correlations between fecal streptococci and Cryptosporidium oocysts and between Giardia and both somatic coliphages and algae were observed in raw surface water samples, but the relationships appear to be watershed-dependent. No significant correlation was obtained between the presence of the protozoa and that of Clostridium perfringens or any of the other indicators. Includes 40 references, tables, figure.