Cryptosporidiosis (Crypto)

What is cryptosporidiosis (crypto)?

Cryptosporidiosis (crypto) is an infection caused by a group of parasites (germs), called cryptosporidium.  Most infections occur in a person’s stomach and intestines (gastrointestinal tract).  Infections can occur in other parts of the body, such as the lungs.  These germs can infect humans, cattle, and other animals.

What are the symptoms of cryptosporidiosis?

  • Diarrhea (loose poop) that may be watery
  • Cramping and abdominal pain
  • Nausea and vomiting
  • Loss of appetite
  • Feeling  unwell
  • Fever

Some people infected do not show any symptoms at all, but can still spread the germs to others.  It takes about 1 to 12 days after the germs enter your body before you feel sick.  Symptoms may come and go, but often completely go away within 30 days for most healthy people.  It may last longer for those with a weakened immune system (how well your body fights infections).

Photo of a person holding their stomach in discomfort

How does cryptosporidiosis spread?

Crypto passes through the stool of an infected person or animal.  Crypto can spread directly or indirectly from person or animal to person through the “fecal-oral route” (poop to mouth) by:

  • Drinking and eating contaminated water and food.
  • Touching your mouth with unclean hands.
  • Putting anything in your mouth that may be contaminated (e.g., toys).
  • Oral-anal sexual activity.

Children under 2 years, animal handlers, travellers, and people who take part in oral-anal sexual activity are at a higher risk of infection.

How long is it contagious?

A person can spread the germ as soon as symptoms begin and up to 2 months after.  The germ can survive on wet surfaces for up to 6 months.  It has a very strong outer shell that makes it very resistant to most disinfectants.

How is cryptosporidiosis treated?

If you or your child has these symptoms, see a health care provider.  Diagnosis involves providing a sample of your stool for testing.

  • For mild symptoms, most people are able to drink plenty of fluids to stay hydrated.
  • For more severe cases, your health care provider might prescribe medications to help with the diarrhea and treat the infection.  Drink plenty of fluids to stay hydrated.

How do I prevent the spread of cryptosporidiosis?

Ways to lower your risk for infection include:

  • Washing your hands often with warm water and soap, especially before and after preparing foods, before eating, and after changing diapers and using the washroom.  Alcohol-based hand rubs (hand sanitizers) do not work against these germs.
  • Practicing safe food handling, including washing all uncooked fruits and vegetables in clean water, and cooking your food properly.  Avoid preparing food if you are sick.
  • Avoiding drinking untreated water.  Travelers, campers, and hikers should use water treatment methods, including boiling the water for 1 full minute.  Consider using filters designed to remove these germs.  The germs are resistant to chlorine.
  • Only drinking pasteurized (treated) milk and milk products.
  • Babies and toddlers should wear special swim diapers or pants when using public waters, such as splash pads and swimming pools.  Avoid using these facilities until 2 weeks after diarrhea-free.
  • Wash contaminated linens, clothing and dryer-safe soft toys as soon as possible.  Use laundry detergent and wash with hot water (45oC/113oF) for at least 20 minutes.  Machine dry on the highest heat setting.
Photo of a person washing an apple

For more information contact the Health Unit or speak to your health care provider.


Heymann, D.L. (Ed.). (2015). Control of communicable diseases manual (20th ed.). Washington, DC: American Public Health Association.

Ontario Ministry of Health and Long-Term Care. (2015). Infectious Diseases Protocol: Appendix A – Cryptosporidiosis. Toronto, ON: Queen’s Printer for Ontario.