Giardia and Cryptosporidium spp. in filtered drinking water supplies.

摘要: Giardia and Cryptosporidium levels were determined by using a combined immunofluorescence test for filtered drinking water samples collected from 66 surface treatment plants in 14 states 1 Canadian province. cysts detected 17% of the 83 effluents. oocysts, observed 27% samples. Overall, or oocysts found 39% treated effluent Despite frequent detection parasites water, microscopic observations suggested that most organisms nonviable. Compliance with filtration criteria outlined Surface Water Treatment Rule U.S. Environmental Protection Agency did not ensure was free oocysts. The average plant turbidity sites which parasite positive 0.19 nephelometric units. Of spp., 78% would have been able to meet regulations Temperature Rule. Evaluation data risk assessment model developed spp. showed 24% utilities examined 1/10,000 annual infection. For cold conditions (0.5 degree C), 46% achieve level.