Cryptosporidiosis is a gastro-intestinal disease caused by the protozoan parasite – Cryptosporidium parvum.

The parasite lives in the digestive tract of people and animals and is spread through faecal matter. The parasite is able to survive outside the body by forming a cyst which protects it from the environment.

What are the symptoms?

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Symptoms start between one and twelve days after the person is infected. 

  • Diarrhoea, which is usually watery and profuse
  • Abdominal cramping
  • Nausea
  • Vomiting
  • Fever
  • Headaches

How is it spread?

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The parasite is transmitted from person to person through contact with infected faeces, either directly (such as between children) or indirectly via contaminated food, water and inanimate objects.

People become infected when they swallow the cysts which have been shed in an infected person's or animal's faeces. Common causes include:

  • Eating food prepared by infected people
  • Drinking from a poor quality water supply e.g. roof or stream water
  • Swimming in water that has been contaminated with faecal matter
  • Contact with pets, especially puppies and kittens with diarrhoea
  • Contact with manure from farm animals
  • Contact with infected people, including children and babies

Another source of infection is consumption of unpasteurised/raw milk.

How is it treated?

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Rest and extra fluid are recommended. There is no effective medicine for the treatment of cryptosporidiosis. Cryptosporidiosis usually resolves itself in less than a month. However, in young children, the elderly and people with immune deficiencies – particularly AIDS patients - the disease can be chronic and serious.

How do I protect myself and others?

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  • Make sure your house is connected to a Council water supply of good quality. If this is not possible use a treatment system that is rated to protect against cryptosporidium.

  • If you have had cryptosporidium you must stay out of swimming pools and spa pools until you have been free from all symptoms for two weeks.

  • Avoid contact with infants, very elderly or ill people while you have diarrhoea.

  • Use sodium hypochlorite (chlorine bleach) to clean your toilet and bathroom fixtures.  Remember that the cryptosporidium cysts are resistant to most cleaning products. 

Wash your hands:

  • After going to the toilet or changing nappies

  • After playing or working with animals

  • Before handling food

Do I need to take time off work, school or preschool?

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  • Stay away from work, school or preschool when you have diarrhoea. 

  • Staff and children of early childhood centres should not return until they have been free from all symptoms for 48 hours.

  • People who work with food or in healthcare should not return until they have been free from all symptoms for 48 hours.


For more information about this illness contact a Health Protection Officer on 0800 221 555.


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Cryptosporidium and giardia - Health New Zealand