||Identification of 'Cryptosporidium' Oocysts in River Water.
Ongerth, J. E. ;
Stibbs, H. H. ;
||Washington Univ., Seattle.;Health Effects Research Lab., Research Triangle Park, NC.
Water pollution ;
Diseases vectors ;
Chemical analysis ;
Spatial distribution ;
Water borne diseases
||Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy.
Water samples were collected from four rivers in Washington State and two rivers in California and examined for the presence of Cryptosporidium oocysts. Oocyst-sized particles were concentrated from 20-liter samples of water by membrane filtration, centrifugation, and differential sedimentation. The particle concentrate was then deposited on a 25-mm-diameter membrane filter for oocyst identification by indirect immunofluorescence assay. The identification procedure had a limit of detection of about five oocysts per liter. Cryptosporidium oocysts were found in each of 11 river water samples examined. Concentrations ranged from 2 to 112 oocysts per liter. The finding of Cryptosporidium oocysts in all samples examined from six western rivers is noteworthy in light of recent reports indicating that Cryptosporidium sp. is a significant agent of human and animal disease. This finding suggests that waterborne oocysts of this parasite are more important than was previously recognized. (Copyright (c) 1987, American Society for Microbiology.)