• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of aemPermissionsJournals.ASM.orgJournalAEM ArticleJournal InfoAuthorsReviewers
Appl Environ Microbiol. May 1990; 56(5): 1423–1428.
PMCID: PMC184422

Effects of ozone, chlorine dioxide, chlorine, and monochloramine on Cryptosporidium parvum oocyst viability.


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.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.2M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Arrowood MJ, Sterling CR. Isolation of Cryptosporidium oocysts and sporozoites using discontinuous sucrose and isopycnic Percoll gradients. J Parasitol. 1987 Apr;73(2):314–319. [PubMed]
  • Berman D, Hoff JC. Inactivation of simian rotavirus SA11 by chlorine, chlorine dioxide, and monochloramine. Appl Environ Microbiol. 1984 Aug;48(2):317–323. [PMC free article] [PubMed]
  • Bingham AK, Jarroll EL, Jr, Meyer EA, Radulescu S. Giardia sp.: physical factors of excystation in vitro, and excystation vs eosin exclusion as determinants of viability. Exp Parasitol. 1979 Apr;47(2):284–291. [PubMed]
  • Campbell I, Tzipori AS, Hutchison G, Angus KW. Effect of disinfectants on survival of cryptosporidium oocysts. Vet Rec. 1982 Oct 30;111(18):414–415. [PubMed]
  • Crawford FG, Vermund SH. Human cryptosporidiosis. Crit Rev Microbiol. 1988;16(2):113–159. [PubMed]
  • Current WL, Reese NC. A comparison of endogenous development of three isolates of Cryptosporidium in suckling mice. J Protozool. 1986 Feb;33(1):98–108. [PubMed]
  • D'Antonio RG, Winn RE, Taylor JP, Gustafson TL, Current WL, Rhodes MM, Gary GW, Jr, Zajac RA. A waterborne outbreak of cryptosporidiosis in normal hosts. Ann Intern Med. 1985 Dec;103(6 ):886–888. [PubMed]
  • Fayer R, Leek RG. The effects of reducing conditions, medium, pH, temperature, and time on in vitro excystation of Cryptosporidium. J Protozool. 1984 Nov;31(4):567–569. [PubMed]
  • Gallaher MM, Herndon JL, Nims LJ, Sterling CR, Grabowski DJ, Hull HF. Cryptosporidiosis and surface water. Am J Public Health. 1989 Jan;79(1):39–42. [PMC free article] [PubMed]
  • Hayes EB, Matte TD, O'Brien TR, McKinley TW, Logsdon GS, Rose JB, Ungar BL, Word DM, Pinsky PF, Cummings ML, et al. Large community outbreak of cryptosporidiosis due to contamination of a filtered public water supply. N Engl J Med. 1989 May 25;320(21):1372–1376. [PubMed]
  • Hoff JC, Rice EW, Schaefer FW., 3rd Comparison of animal infectivity and excystation as measures of Giardia muris cyst inactivation by chlorine. Appl Environ Microbiol. 1985 Oct;50(4):1115–1117. [PMC free article] [PubMed]
  • Nime FA, Burek JD, Page DL, Holscher MA, Yardley JH. Acute enterocolitis in a human being infected with the protozoan Cryptosporidium. Gastroenterology. 1976 Apr;70(4):592–598. [PubMed]
  • Peeters JE, Mazás EA, Masschelein WJ, Villacorta Martiez de Maturana I, Debacker E. Effect of disinfection of drinking water with ozone or chlorine dioxide on survival of Cryptosporidium parvum oocysts. Appl Environ Microbiol. 1989 Jun;55(6):1519–1522. [PMC free article] [PubMed]
  • Reduker DW, Speer CA. Factors influencing excystation in Cryptosporidium oocysts from cattle. J Parasitol. 1985 Feb;71(1):112–115. [PubMed]
  • Schupp DG, Erlandsen SL. A new method to determine Giardia cyst viability: correlation of fluorescein diacetate and propidium iodide staining with animal infectivity. Appl Environ Microbiol. 1987 Apr;53(4):704–707. [PMC free article] [PubMed]
  • Tzipori S. Cryptosporidiosis in animals and humans. Microbiol Rev. 1983 Mar;47(1):84–96. [PMC free article] [PubMed]

Articles from Applied and Environmental Microbiology are provided here courtesy of American Society for Microbiology (ASM)


Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...


Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...