Effects of ozone, chlorine dioxide, chlorine, and monochloramine on Cryptosporidium parvum oocyst viability.
TLDR
The data indicate that C. parvum oocysts are 30 times moreresistant to ozone and 14 times more resistant to chlorine dioxide than Giardia cysts exposed to these disinfectants under the same conditions.Abstract:
Purified Cryptosporidium parvum oocysts were exposed to ozone, chlorine dioxide, chlorine, and monochloramine. Excystation and mouse infectivity were comparatively evaluated to assess oocyst viability. Ozone and chlorine dioxide more effectively inactivated oocysts than chlorine and monochloramine did. Greater than 90% inactivation as measured by infectivity was achieved by treating oocysts with 1 ppm of ozone (1 mg/liter) for 5 min. Exposure to 1.3 ppm of chlorine dioxide yielded 90% inactivation after 1 h, while 80 ppm of chlorine and 80 ppm of monochloramine required approximately 90 min for 90% inactivation. The data indicate that C. parvum oocysts are 30 times more resistant to ozone and 14 times more resistant to chlorine dioxide than Giardia cysts exposed to these disinfectants under the same conditions. With the possible exception of ozone, the use of disinfectants alone should not be expected to inactivate C. parvum oocysts in drinking water.read more
Citations
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Journal ArticleDOI
Efficiency of chlorine and UV in the inactivation of Cryptosporidium and Giardia in wastewater
TL;DR: UV is a promising alternative to Chlorine in removing Cryptosporidium and Giardia from waste water withGiardia responded very well to UV irradiations with almost 0 percent remaining viable after a low dose of UV.
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The prevalence of Cryptosporidium and Giardia spp. in fecal samples from free-ranging white-tailed deer (Odocoileus virginianus) in the southeastern United States
TL;DR: It is demonstrated that white-tailed deer shed cysts and oocysts of both parasites in the environment and must be considered potential sources of contamination.
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Source tracking identifies deer and geese as vectors of human-infectious Cryptosporidium genotypes in an urban/suburban watershed.
TL;DR: It is suggested that deer, geese, and WWTPs are appropriate targets for source water protection in the Wissahickon watershed as vectors of human-infectious genotypes in this watershed.
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Cryptosporidium parvum studies with dairy products.
Ming Qi Deng,Dean O. Cliver +1 more
TL;DR: This study was conducted to model the transfer of C. parvum oocysts from contaminated water via food contact surfaces into yogurt and ice-cream, as well as to examine oocyst survival.
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An immunomagnetic separation polymerase chain reaction assay for rapid and ultra‐sensitive detection of Cryptosporidium parvum in drinking water
TL;DR: This immunomagnetic separation-polymerase chain reaction assay can detect the presence of a single seeded oocyst in 5-100-1 samples of drinking water, thereby assuring the absence of C. parvum contamination in the sample under analysis.
References
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Book
Standard methods for the examination of water and wastewater
TL;DR: The most widely read reference in the water industry, Water Industry Reference as discussed by the authors, is a comprehensive reference tool for water analysis methods that covers all aspects of USEPA-approved water analysis.
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Determination of ozone in water by the indigo method
TL;DR: In this article, the decolorization of indigo trisulfonate (600 nm, pH below 4) was used to determine the concentration of aqueous ozone in the range 0.005 −30 mg 1−1.
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Acute enterocolitis in a human being infected with the protozoan Cryptosporidium.
TL;DR: It is suggested, on the basis of the severity of the clinical symptoms, and on the pathological changes in the rectum, that the organism in this case is likely to have been the cause of the enterocolitis and thus to have was a pathogen rather than a commensal.
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Isolation of Cryptosporidium oocysts and sporozoites using discontinuous sucrose and isopycnic Percoll gradients.
TL;DR: Techniques for the large-scale isolation of Cryptosporidium oocysts and sporozoites, obtained from the feces of experimentally infected Holstein calves, were developed employing discontinuous sucrose gradients and isopycnic Percoll gradients.
Journal ArticleDOI
Large Community Outbreak of Cryptosporidiosis Due to Contamination of a Filtered Public Water Supply
Edward B. Hayes,Thomas Matte,Thomas R. O'Brien,Thomas W. McKinley,Gary S. Logsdon,Joan B. Rose,Beth L. P. Ungar,David M. Word,Margaret A. Wilson,Earl G. Long,Eugene S. Hurwitz,Dennis D. Juranek +11 more
TL;DR: Current standards for the treatment of public water supplies may not prevent the contamination of drinking water by Cryptosporidium, with consequent outbreaks of cryptosporidiosis, it is concluded.