Authored by Revere Health

Crypto: Symptoms, Diagnosis & Treatment

October 5, 2016 | Gastroenterology

Swimming Pools and Other Recreational Waters: A Haven for Hardy Parasites

With 2016 as the hottest year on record, there is no doubt your family enjoyed a lot of time cooling off in the water. Public and private swimming pools, mountain lakes and rushing rivers provide a refreshing sanctuary for Utahns trying to beat the heat. But they also offer sanctuary to a microscopic parasite the Centers for Disease Control and Prevention dub “the leading cause of waterborne disease outbreaks linked to recreational water in the United States,” – Cryptosporidium.

Understanding cryptosporidiosis

Cryptosporidium parasites are tough little germs that cause the diarrheal disease cryptosporidiosis. Both the parasite and the illness are known as “Crypto.” Crypto is found in every region of the United States and thrives in water, food and soil. It can be found on surfaces or dirty hands that have been contaminated with the feces of humans or animals infected with the parasite.

This rugged parasite has a protective outer shell that allows it to survive outside the body for long periods of time. This shell also makes the germ highly tolerant to chlorine and chlorine-based disinfectants, which explains why it can survive for long periods in chlorinated swimming pool water and drinking water. Cryptosporidia “can’t be effectively removed by many filters and can also survive in the environment for many months at varying temperatures, though the parasite can be destroyed by freezing or boiling,” adds  Mayo Clinic.
Cryptosporidia enter the body through the mouth and make their way to the intestinal tract where they burrow into the lining. Eventually the highly contagious germs are passed into the feces. “An infected person can shed 10,000,000 to 100,000,000 Crypto germs in a single bowel movement,” reports the CDC. This shedding begins when the characteristic diarrhea starts and can continue for weeks, even after the symptoms ease up.

How is Crypto spread?

Although there are several ways to transmit the parasite, ingesting contaminated drinking water and recreational water is the most common. You only need to swallow as few as 10 Crypto germs to become infected.

Crypto is most commonly contracted by:

  • Swallowing water in swimming pools, streams, ponds, lakes and rivers contaminated with Crypto
  • Swallowing water, ice or beverages contaminated with feces from infected humans or animals
  • Eating undercooked food contaminated with Crypto
  • Drinking unpasteurized or raw juices or dairy products contaminated with Crypto
  • Touching surfaces or objects that have been in contact with feces from an infected person or animal and then touching your mouth with your hands

What are the symptoms of Crypto?

Infection symptoms typically begin two to 10 days after exposure to the parasite and include:

  • Watery diarrhea
  • Painful stomach cramps
  • Lack of appetite
  • Dehydration
  • Nausea
  • Vomiting
  • Fever
  • Weight loss


Some people with Crypto will have no symptoms at all, although they remain contagious. People with healthy immune systems usually find their symptoms abating within two weeks, but they may come and go for up to a month. If you or a family member develop watery diarrhea that does not get better within a few days, it’s important to see your gastroenterologist immediately.

Diagnosing and treating Crypto

Because the parasite can be shed irregularly in stool, your doctor may gather a few stool samples on different days to diagnose a Crypto infection. Most healthy people diagnosed with cryptosporidiosis recover without treatment, provided they stay well hydrated to replenish the fluids lost due to diarrhea.

You might take an over-the-counter anti-diarrheal medication, or your doctor may prescribe an anti-parasitic drug called nitazoxanide to treat the diarrhea. It’s important to eat a well-balanced diet, avoid dehydrating liquids like coffee and alcohol, and practice good hand-washing hygiene to avoid spreading the parasite to other people.
Do you suspect a parasitic infection might be to blame for a recent bout of diarrhea? Revere Health’s gastroenterologists are ready to help. We diagnose and treat a wide variety of disorders of the gastrointestinal tract and offer compassionate, patient-centered care in several Utah locations.


If you need a colonoscopy, make an appointment with Revere Health. Our gastroenterologists have performed over 200,000 comprehensive colonoscopies. We use the latest technology and equipment to ensure accurate results.



The Live Better Team


The Live Better Team

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This information is not intended to replace the advice of a medical professional. You should always consult your doctor before making decisions about your health.