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IDENTIFICATION OF 'CRYPTOSPORIDIUM' OOCYSTS IN RIVER WATER
Citation:
Ongerth, J. AND H. Stibbs. IDENTIFICATION OF 'CRYPTOSPORIDIUM' OOCYSTS IN RIVER WATER. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-87/073 (NTIS PB88104161), 1987.
Description:
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.)