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
Investigations from Northern Greece on mussels cultivated in areas proximal to wastewaters discharges, as a potential source for human infection with Giardia and Cryptosporidium
TL;DR: The results suggest that the likelihood that mussels from these locations act as vehicles of human infection for Giardia and Cryptosporidium seems low.
Book ChapterDOI
Ozone: A Powerful Tool for the Fresh Produce Preservation
TL;DR: O3 has attracted considerable commercial interest, especially because ozone does not leave any residues on the treated produce and it is also accepted by many organic grower organizations as mentioned in this paper, however, several contradictions regarding the efficacy of this technology are often found in the literature and further research is still needed.
Journal ArticleDOI
The parasite specific substitution matrices improve the annotation of apicomplexan proteins
TL;DR: The parasite specific substitution matrices have higher specificity for apicomplexan proteins and are helpful in detecting the orthologs missed by BLOSUM matrices and thereby improve the annotation of apicosporidium proteins which are hypothetical or with unknown function.
Dissertation
Water Quality Impacts of Pure Chlorine Dioxide Pretreatment at the Roanoke County (Virginia) Water Treatment Plant
TL;DR: In this paper, the authors discuss the effects of KnowLEDGEMENTs on people's perceptions of others' beliefs and behaviors.............................................................................................................................. ii ACKNOWLEDGMENTS
Journal ArticleDOI
The evolution of microbiology in the drinking water industry
TL;DR: The primary focus of this article is on microorganisms (pathogens) that cause disease such as Cryptosporidium spp.
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.
Journal ArticleDOI
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.
Journal ArticleDOI
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.
Journal ArticleDOI
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.