What is Cryptosporidiosis?

Cryptosporidiosis is a diarrheal illness caused by a microscopic parasite, Cryptosporidium parvum. The parasite lives in the intestines of humans and animals and is passed in the stool of an infected animal especially cattle and sheep, or person. The parasite is able to survive outside of the body for a long time because it has an outer shell that protects it. This shell makes the parasite very resistant to chlorine disinfection.

What are the Signs and Symptoms of Cryptosporidiosis?

Some people who are infected with Cryptosporidiosis do not show any symptoms. Other people will have watery diarrhea lasting one to two weeks, abdominal discomfort, nausea, vomiting, fatigue, low-grade fever, dehydration, weight loss and inability to eat.

How long after contact with Cryptosporidiosis will symptoms appear?

Symptoms will usually develop between one to 12 days (average seven days) after swallowing the parasite.

How long will symptoms last?

In healthy people, the illness will usually last one to four weeks. Symptoms may come and go within this time period. In people with weakened immune systems, infection can be chronic and life threatening.

How is Cryptosporidiosis Spread?

Infection happens after swallowing the parasite. Cryptosporidium may be found in soil, food, water or surfaces that have been contaminated with the feces from an infected human or animal. Cryptosporidium can be spread:

  • By eating food or drinking water that has been contaminated by the feces of people or animals that are infected with Cryptosporidium.
  • By swallowing recreational water contaminated with Cryptosporidium such as swimming pools, hot tubs, jacuzzis, fountains, lakes, rivers, springs, ponds, or streams that can be contaminated with sewage or feces from humans or animals. Note – Cryptosporidium is chlorine resistant and can live for days in pools.
  • By eating uncooked and unwashed food contaminated with Cryptosporidium.

How is Cryptosporisiosis infection prevented?

  • Wash hands thoroughly with soap and water especially after using the toilet, changing diapers, following contact with animals and before handling or eating food.
  • Do not swim in recreational waters such as pools, hot tubs or Jacuzzi if you are experiencing diarrhea. The parasite is very resistant to chlorine and can live for days in chlorine-treated swimming pools and would then infect others who swam in the same water. Avoid ingesting recreational water.
  • Avoid drinking water from rivers, creeks, lakes, shallow wells, springs, ponds and streams. If the water has not been properly treated, don’t drink it.
  • Do not use untreated ice or drinking water when travelling in countries where the water supply might be unsafe.
  • Avoid food that might be contaminated. Always wash vegetables and fruits with treated water before you eat them.
  • Do not drink unpasteurized milk or milk products.
  • When traveling, camping or hiking or if a “boil water” advisory has been issued, bring the water to a boil for one full minute. This water should be used for drinking, brushing teeth, rinsing dentures or contact lenses, making ice cubes, washing uncooked fruits and vegetable and in recipes requiring water. Dishes should be washed in water that has been boiled.
  • Avoid sexual activity that involves anal contact.

Information adapted from:

  • Centers for Disease Control and Prevention, “Cryptospordiosis”, January 2009. Accessed March 2010.
  • Canadian Institute of Public Health Inspectors “Cryptosporidiosis”, August 2004
  • Heymann, D.L., 2008. Control of Communicable Diseases Manual, 19th Edition. Washington, District of Columbia: American Public Health Association