What is Cryptosporidium infection?
Cryptosporidium is a parasite known to cause illness that affects the stomach. The parasite can make both humans and animals sick. Cryptosporidium, or "Crypto" for short, can be found in water, food, soil or on surfaces or hands that have been contaminated with the feces of humans or animals infected with the parasite.

Drinking from Stream
How common is Cryptosporidium infection?
Cryptosporidium is frequently the leading cause of waterborne disease outbreaks, linked to recreational water in the United States. The parasite is found in every region of the United States and throughout the world. People who are most likely to become infected with Cryptosporidium include:

  • Children who attend childcare centers, including diaper-aged children
  • Childcare workers
  • Parents of infected children
  • People who take care of other people with Cryptosporidium
  • International travelers
  • Backpackers, hikers, and campers who drink unfiltered, untreated water
  • People who drink from untreated shallow, unprotected wells
  • People, including swimmers, who swallow water from contaminated sources
  • People who work with cattle and other livestock
  • People exposed to human poop through sexual contact

What are the symptoms of Cryptosporidium?
Symptoms of Cryptosporidium infection generally begin 2 to 10 days (average 7 days) after being exposed to the parasite. Symptoms include:

  • Watery diarrhea
  • Stomach cramps or pain
  • Dehydration
  • Nausea
  • Vomiting
  • Fever
  • Weight loss

Symptoms usually last about 1 to 2 weeks (with a range of a few days to 4 or more weeks) in people with healthy immune systems. Some people with Cryptosporidium will have no symptoms at all.

How is Cryptosporidium spread?
People must swallow or eat the parasite to become infected. Cryptosporidium is usually spread through the following:  

  • Drinking or swallowing water from swimming pools or hot tubs. Cryptosporidium is a very hardy parasite and can survive in treated water.

  • People who become infected will have the parasite in their stool. Ill people who do not wash their hands after using the bathroom or changing diapers can spread the parasite. 

  • Cattle and some pets, including dogs and cats, can be infected and spread the parasite to you through their poop. 

  • Contact with an infected person’s poop during sexual activity can spread the parasite to others.

Swimming Pool
When to call your healthcare provider
Contact your healthcare provider if you have diarrhea that has lasted for over 3 days, or if you have a high fever, have blood in your stool, or if you are becoming dehydrated from having diarrhea and/or vomiting.

How is Cryptosporidium diagnosed?
Cryptosporidium infection is diagnosed when a laboratory tests detects Cryptosporidium in a stool sample.

Baby cows
How is Cryptosporidium infection treated?
For most people, symptoms will go away on their own within 1-3 weeks.  It is important to drink extra fluids to avoid dehydration. People with chronic illnesses (i.e. AIDS/ HIV patients) may not be able to recover as quickly. Call your doctor if symptoms do not go away or become worse.

How do I avoid Cryptosporidium infection?

  • Do not drink water from lakes, streams, rivers, etc. unless it has been treated to kill or remove Cryptosporidium.  
  • Do not swallow water from swimming pools or spas.
  • Wash hands before preparing and serving food.  
  • Always wash your hands after using the bathroom.  
  • Always wash hands after changing diapers and toilet training.

Is there anything special I need to know?

Do not prepare food for others.

Stay home from work. Especially if your job involves handling food, caring for small children, or working with patients in a healthcare setting.  

Children who have Cryptosporidium should not go to child care settings—especially if they have diarrhea.

Cryptosporidium can still be shed in poop even after diarrhea has stopped.  Do not swim for up to 2 weeks after diarrhea stops.


Special Circumstances

Food handlers - Food handlers should be excluded from work until at least 24 hours after diarrhea has resolved and adequate hygiene can be maintained.

Childcare - Children and staff members with Cryptosporidium who have diarrhea should be excluded until at least 24 hours after diarrhea has resolved. Parents of cases should be counseled not to take their children to another childcare center during this period of exclusion.

Meticulous hand washing should be done after diaper changes and toileting children.

Why does public health investigate Cryptosporidium cases?

It is the responsibility of the local health department to investigate Cryptosporidium in the community. The health department keeps track of how many people are reported with the disease and works to limit the number of people exposed.  

Most people infected with Cryptosporidium are single, sporadic cases. However, sometimes there are outbreaks when two or more people become ill from the same source. The health department monitors Cryptosporidium in an attempt to identify and stop outbreaks of the disease.