Cryptosporidiosis is a parasitic disease commonly identified as Crypto. The most common route of infection is through fecal/oral exposure. Not clinically identified till 1976, Crypto is today the most common waterborne disease and is found worldwide. Children 1‐9 are most often infected. One recorded outbreak resulted in 400,000 confirmed cases. A 2008 outbreak in the Dallas/Ft Worth metroplex resulted in 400 confirmed cases. Many of the 2008 cases were the result of swallowing fecal infected water while swimming in public and semi‐public pools. The ingested cysts make their way to the small intestine where the infection grows.

Crypto is a short term acute infection whose symptoms appear within 2-10 days. The average length of time between exposure and appearance of symptoms is 7 days. Symptoms include watery diarrhea, cramps, nausea, vomiting, low fever, and dehydration. Symptoms normally disappear within 2 weeks to 1 month. The person remains infectious until all symptoms disappear. Your doctor may be able to treat the symptoms to make you more comfortable. There is no reliable treatment for the condition itself.

While unpleasant, Crypto does not pose a serious health threat to healthy adults. Persons with compromised immune systems and young children, whose immune systems have not fully developed, may suffer severe symptoms and should see a doctor. Cases are rarely, but can be, fatal.

Be aware that swimming pool water cannot be tested on‐site for Crypto. Crypto is chlorine resistant and can survive the upper legal limits of normal swimming pool sanitizer requirements. Crypto is small enough to escape normal water filtration systems. Do not swim in pools that are shared if you display any of the above symptoms.

Protect yourself and others from being infected

  • Wash your hands after going to the restroom.
  • Do not swim in shared pools if you are displaying symptoms.
  • Do not leave a child in daycare that is displaying symptoms.
  • Do not change diapers poolside.
  • When swimming in shared pools do not swallow pool water.
  • Do not bath small children together if one of the children is displaying symptoms.
  • Do not engage in food preparation for others if you are displaying symptoms.

Additional Resources