Giardia cyst concentrations were determined in an inventory of 153 raw and 91 chlorinated drinking water samples collected at 86 sites from throughout the western Canadian province of British Columbia.
Sixty-four percent of raw water samples were cyst positive (69% of sites).
Cyst concentrations were lower in chlorinated than in raw water.
The viability of cysts in drinking water samples assessed by infectivity in Mongolian gerbils (Meriones unguiculatus) was decreased in chlorinated water.
Two rural communities using Giardia-contaminated surface drinking water sources were selected for longitudinal studies including drinking water testing and serological studies of residents.
Three hundred thirty-six raw and treated samples from these communities were collected over 24 months.
Cyst concentrations and viability were assessed in a 12-month study of each community.
Parasite concentrations were lower in chlorinated water than in raw water in both communities.
Cyst concentrations were lower in reservoir-settled water than in raw water.
Viability, assessed by animal infectivity and corrected for inoculum, decreased following reservoir settling as well as after chlorination.
A bolus or spiking phenomenon of cysts was observed in both community drinking water systems and deserves further study.
A striking seasonal pattern was seen in one community but not in the second.
The seroprevalence data and number of laboratory-confirmed cases identified in each year-long ...
Mots-clés Pascal : Système distribution, Eau potable, Contamination biologique, Kyste, Concentration, Viabilité, Parasite, Zone rurale, Variation saisonnière, Canada, Amérique du Nord, Amérique, Colombie britannique, Diplomonadida, Protozoa, Giardia
Mots-clés Pascal anglais : Distribution system, Drinking water, Biological contamination, Cyst, Concentration, Viability, Parasite, Rural area, Seasonal variation, Canada, North America, America, British Columbia, Diplomonadida, Protozoa
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 96-0284803
Code Inist : 002B30A02A. Création : 199608.