Affiliation:
1. School of Medicine, University of Washington, Seattle 98195.
Abstract
Water samples were collected from four locations on two rivers in Washington State and analyzed by membrane filtration-immunofluorescence assay to establish Cryptosporidium oocyst concentrations. Sampling locations were selected to evaluate effects of watershed character, from pristine mountain to downstream agricultural, on oocyst concentrations. Samples were collected at six biweekly intervals from late June to early September, with two additional sets of five samples taken on separate days (one set taken at bihourly intervals and one set taken simultaneously). Cryptosporidium oocysts were found in 34 of 35 samples at concentrations ranging from about 0.2 to 65 oocysts per liter. Oocyst concentrations were highest early in the sampling period, when they were influenced by postrainfall runoff, and decreased through the summer months. Oocyst concentrations found in ten samples collected on two days (5 samples per day) showed no short-term variations. Oocyst concentrations and oocyst production per square mile (ca. 2.6 km2) of watershed found in water draining a controlled public water supply watershed were the lowest observed. The concentrations and production rates for drainage from an adjacent, comparable, but uncontrolled watershed were nearly 10 times higher. The concentration and production rates of the downstream area influenced by dairy farming were nearly 10 times higher than rates at the upstream stations. The data showed clearly that oocyst concentrations were consistently observed above the detection limit of the analytical method, about 0.1 oocysts per liter; that oocyst concentrations were continuous as opposed to intermittent; and that watershed character and management affected surface water oocyst concentrations significantly.
Publisher
American Society for Microbiology
Subject
Ecology,Applied Microbiology and Biotechnology,Food Science,Biotechnology
Reference27 articles.
1. Cryptosporidiosis in man, domestic animals and birds: a review;Angus K. W.;J. R. Soc. Med.,1983
2. Cryptosporidiosis among children attending daycare centers;Centers for Disease Control.;Morbid. Mortal. Weekly Rep.,1984
3. Colbourne J. S. 1989. Thames water utilities experience with Cryptosporidium p. 275-278. In Proceedings of the 1990 WQTC-17. American Water Works Association Denver.
4. Current W. L. 1984. Cryptosporidium and cryptosporidiosis p. 355-373. In M. S. Gottlieb and J. E. Groopman (ed.) Acquired immune deficiency syndrome. Allen R. Liss Inc. New York.
5. Human cryptosporidiosis in immunodeficient persons;Current W. L.;N. Engl. J. Med.,1983
Cited by
135 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献