--- title: Swimming Pools May Be Driving More Crypto Disease Outbreaks description: The CDC warns that disease outbreaks associated with the parasite Cryptosporidium are increasing, and swimming pools may be to blame. canonical: https://time.com/5618222/cryptosporidium-swimming-pools/ author: Jamie Ducharme article:opinion: false article:content_tier: free article:published_time: 2019-07-01T15:25:09.000Z article:modified_time: 2026-02-23T23:53:36.119Z article:section: Health og:title: Swimming Pools May Be Driving More Disease Outbreaks, CDC Warns og:description: Because of a fecal parasite og:url: https://time.com/5618222/cryptosporidium-swimming-pools/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt9ebf23a037154533/6989ff5d4ee2623adb315e60/swimming-pools.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 og:image:width: 1200 og:image:height: 675 og:image:alt: Girl jumping into swimming pool with pink flamingo og:type: article twitter:card: summary_large_image twitter:title: Swimming Pools May Be Driving More Disease Outbreaks, CDC Warns twitter:description: Because of a fecal parasite twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt9ebf23a037154533/6989ff5d4ee2623adb315e60/swimming-pools.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 ---  # A Fecal Parasite Is Causing More Disease Outbreaks, and Swimming Pools May Be to Blame, CDC Says  by [Jamie Ducharme](https://time.com/author/jamie-ducharme/)  ## Jamie Ducharme Ducharme is a contributor to TIME. Jul 1, 2019 3:25 PM UTC  USA, Arizona USA, ArizonaGetty Images  by [Jamie Ducharme](https://time.com/author/jamie-ducharme/)  ## Jamie Ducharme Ducharme is a contributor to TIME. Jul 1, 2019 3:25 PM UTC A recent announcement from the U.S. Centers for Disease Control and Prevention (CDC) may put a damper on summer fun. A fecal parasite often spread by swimming is causing an increasing number of illness outbreaks, [the agency says](https://www.cdc.gov/media/releases/2019/p0627-outbreaks-diarrhea-summertime.html). The number of [disease outbreaks](https://time.com/5364788/shades-of-sherwood-crypto-outbreak/) involving the parasite _Cryptosporidium_, also known as Crypto, increased by about 13% each year from 2009 to 2017, according to [a new report](https://www.cdc.gov/mmwr/volumes/68/wr/mm6825a3.htm?s%5Fcid=mm6825a3%5Fw%5C) from the CDC. People can become ill with cryptosporidiosis after exposure to contaminated human or animal fecal matter, developing symptoms including nausea, cramps and diarrhea that can last weeks and lead to serious malnutrition and dehydration. Crypto outbreaks are still fairly uncommon in U.S. states and Puerto Rico: 444 were reported from 2009 to 2017, resulting in about 7,500 illnesses, almost 300 hospitalizations and one death. In the U.S., more than half of all recent Crypto-related illnesses could be traced back to swimming pools, water playgrounds and other treated-water recreation areas, since people may swallow contaminated water in these places. As such, infections are most common in July and August, the CDC says. (Untreated swimming waters, such as lakes and rivers, may also be a breeding ground for bacteria that cause illnesses such as _E. coli_, norovirus and Shigella, the CDC [warned last summer](https://time.com/5325136/swimming-untreated-water-disease-outbreaks/).) Other Crypto outbreaks have been traced back to cattle farms, childcare centers and consumption of unpasteurized milk and apple cider, according to the CDC. With known outbreaks on the rise—and even more likely going unreported—the CDC emphasizes that no one should swim or allow kids to swim if they are sick with diarrhea. Swimmers should also take care not to swallow water, the CDC says. In addition, sick children should be kept home from school or childcare; people who are in contact with animals should wash their hands, clothes and shoes often; and people shouldn’t drink unpasteurized milk or apple cider. ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/5618222/cryptosporidium-swimming-pools/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/5618222/cryptosporidium-swimming-pools/"},"headline":"A Fecal Parasite Is Causing More Disease Outbreaks, and Swimming Pools May Be to Blame, CDC Says","datePublished":"2019-07-01T15:25:09.000Z","dateModified":"2026-02-23T23:53:36.119Z","description":"Read this before your next dip","url":"https://time.com/5618222/cryptosporidium-swimming-pools/","keywords":["Public Health"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/blt9ebf23a037154533/6989ff5d4ee2623adb315e60/swimming-pools.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Jamie Ducharme","jobTitle":"Ducharme is a contributor to TIME.","url":"https://time.com/author/jamie-ducharme/"}],"articleSection":"Health","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/blt9ebf23a037154533/6989ff5d4ee2623adb315e60/swimming-pools.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"Girl jumping into swimming pool with pink flamingo","caption":"Girl jumping into swimming pool with pink flamingo","creditText":"Getty Images","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/health/","name":"Health"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/public-health/","name":"Public Health"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/5618222/cryptosporidium-swimming-pools/","name":"A Fecal Parasite Is Causing More Disease Outbreaks, and Swimming Pools May Be to Blame, CDC Says"}}]}] ```