cryp·​to·​spo·​rid·​i·​um ˌkrip-tō-spȯr-ˈi-dē-əm How to pronounce cryptosporidium (audio)
plural cryptosporidia ˌkrip-tō-spȯr-ˈi-dē-ə How to pronounce cryptosporidium (audio)
: any of a genus (Cryptosporidium of the order Coccidia) of protozoans parasitic in the gut of vertebrates including humans and sometimes causing diarrhea

Example Sentences

Recent Examples on the Web Children playing in the yard and adults gardening are particularly at risk of picking up diseases and parasites like campylobacteriosis, cryptosporidium and toxocariasis, the agency warns. Dallas News, 3 May 2022 Oocysts of cryptosporidium stained using the Ziehl-Nielson stain. Rebecca Kreston, Discover Magazine, 26 May 2014 The pathogens, toxoplasma gondii, cryptosporidium parvum and giardia enterica, end up in waterways when feces from infected animals contaminate the water. Elizabeth Weise, USA TODAY, 28 Apr. 2022 The microfiltration membrane takes care of and removes 99.999999% of waterborne bacteria (including E. coli and salmonella) and 99.999% of waterborne parasites (including giardia and cryptosporidium). Chris Hachey, BGR, 26 Nov. 2021 Giardia and cryptosporidium are two other intestinal parasites that are actually not uncommon in the U.S., both of which are microscopic parasites that wouldn't cause worms but could cause diarrhea and other GI symptoms, says Dr. Sears. Casey Gueren, SELF, 19 Aug. 2021 If you have been diagnosed with cryptosporidium, don't go back in the water until two weeks after diarrhea has completely stopped. Rachel Trent, CNN, 3 July 2021 Olympic National Park recommends you either boil or filter water before drinking it (treating the coastal water sources with iodine or chlorine will not kill the cryptosporidium). oregonlive, 23 June 2021 According to the specs, the 0.1-micron absolute filtration removes 99.99999% of all bacteria (salmonella, leptospirosis, cholera, E.coli, and more) and protozoa, such as giardia and cryptosporidium. Danielle Bernabe, Fortune, 29 May 2021 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'cryptosporidium.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


borrowed from New Latin, genus name, from crypto- crypto- + sporidium "small spore," from spora spore entry 1 + -idium -idium

Note: Taxon introduced by the American physician and parasitologist Ernest E. Tyzzer (1875-1965) in "A sporozoan found in the peptic glands of the common mouse," Proceedings of the Society for Experimental Biology and Medicine, vol. 5 (1907-08), pp. 12-13.

First Known Use

1910, in the meaning defined above

Time Traveler
The first known use of cryptosporidium was in 1910

Dictionary Entries Near cryptosporidium

Cite this Entry

“Cryptosporidium.” Dictionary, Merriam-Webster, Accessed 31 Jan. 2023.

Medical Definition


cryp·​to·​spo·​rid·​i·​um ˌkrip-tō-spȯr-ˈid-ē-əm How to pronounce cryptosporidium (audio)
capitalized : a genus of protozoans of the order Coccidia that are parasitic in the gut of many vertebrates including humans and that sometimes cause diarrhea especially in individuals who are immunocompromised (as in AIDS)
plural cryptosporidia -ē-ə How to pronounce cryptosporidium (audio) : any protozoan of the genus Cryptosporidium
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