Effects of ozone, chlorine dioxide, chlorine, and monochloramine on Cryptosporidium parvum oocyst viability.
Reads0
Chats0
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
More filters
Journal ArticleDOI
Limiting swimming pool outbreaks of cryptosporidiosis - the roles of regulations, staff, patrons and research
TL;DR: Key barriers to limiting swimming pool-associated outbreaks of cryptosporidiosis are a lack of uniform national and international standards, poor adherence and understanding of regulations governing staff and patron behaviour, and low levels of public knowledge and awareness.
Journal ArticleDOI
Design Criteria for Inactivation of Cryptosporidium by Ozone in Drinking Water
TL;DR: In this article, a set of criteria was established for selecting data from diverse sources and experimental protocols with the objective of compiling comparable data, and several kinetic models were evaluated ranging from the 4-parameter Hom “Power Law model to the single parameter Chick model.
Journal ArticleDOI
Low pressure ultraviolet studies for inactivation of Giardia muris cysts
TL;DR: A comparison of in vitro excystation and animal infectivity was performed for assessing cyst viability after exposure to low‐pressure u.v. irradiation to confirm earlier ultraviolet (u.v.) light inactivation studies performed on Giardia cysts using excy station as the viability indicator.
Journal ArticleDOI
Characterization of Cryptosporidium parvum by matrix-assisted laser desorption ionization-time of flight mass spectrometry.
TL;DR: In this paper, a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was used to investigate whole and freeze-thawed Cryptosporidium parvum oocysts.
Journal ArticleDOI
Effects of carbon dioxide and ozone treatments on the volatile composition and sensory quality of dry-cured ham.
R.K. Sekhon,Mark W. Schilling,T.W. Phillips,R.M.J. Aikins,Md. Mahbub Hasan,Ramakrishna Nannapaneni,W.B. Mikel +6 more
TL;DR: It was revealed that there were minimal aroma/flavor differences among the ham treatments between 0 and 60% CO(2) for 96 h; and also between 0 to 175 ppm O(3).
References
More filters
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.