Where It Comes From
Runoff or leaks of sewage/manure into rivers, lakes, and drinking-water sources; infected swimmers; childcare settings; livestock and wildlife [1][3][4].
How You Are Exposed
Swallowing contaminated pool, splash pad, or natural water; drinking untreated or inadequately treated water; eating contaminated food; touching surfaces/animals and then your mouth [1][2][4].
Why It Matters
Causes watery diarrhea, stomach cramps, nausea, fever; illness can last 1–2 weeks or longer; dehydration risk; very small number of germs can make you sick; oocysts survive >7 days in properly chlorinated pools [1][2][4].
Who Is at Risk
Young children, pregnant people, older adults, travelers; people with weakened immune systems (HIV, transplant, cancer) [1][4].
How to Lower Your Exposure
Don’t swallow water when swimming; keep sick kids out of pools for 2 weeks after diarrhea stops; wash hands after restroom/diapering/animal contact; follow boil-water advisories; at home, boil water 1 minute or use filters labeled “NSF/ANSI 53 or 58” for cyst removal or reverse osmosis; drink pasteurized beverages; wash produce [1][2][5][4].
References
- [1]CDC. Cryptosporidium (Crypto) – About. https://www.cdc.gov/cryptosporidium/index.html
- [2]CDC. Crypto and Swimming. https://www.cdc.gov/healthywater/swimming/illnesses/cryptosporidium.html
- [3]EPA. Pathogens and Indicators in Drinking Water. https://www.epa.gov/ground-water-and-drinking-water/basic-information-about-pathogens-and-indicators-drinking-water
- [4]WHO. Cryptosporidiosis Fact Sheet. https://www.who.int/news-room/fact-sheets/detail/cryptosporidiosis
- [5]CDC. Choosing Home Water Filters. https://www.cdc.gov/healthywater/drinking/home-water-treatment/water-filters.html