Health conditions

Cryptosporidium infection (Cryptosporidiosis)

  • Cryptosporidium infection (Cryptosporidiosis) is a form of gastroenteritis (gastro).
  • You can have the disease and spread it without feeling ill yourself.
  • The main symptoms are diarrhoea, stomach cramps, nausea and vomiting.
  • Good hygiene can help stop it spreading.

Cryptosporidium infection (Cryptosporidiosis) is a form of gastroenteritis (gastro) that is caused by a tiny parasite called Cryptosporidium. The parasite is a single-celled organism that is found in faeces (poo) of infected humans and some animals.

Cryptosporidium can infect humans and over 45 different animal species including cattle, sheep, dogs, cats, birds and fish. This organism has been found in more than 50 countries on 6 continents.

How do you get Cryptosporidium infection?

You can get Cryptosporidium infection by putting anything in your mouth that has been directly or indirectly contaminated with animal or human faeces.

Infection most often occurs by:

  • swallowing polluted water from rivers, streams, springs, ponds, lakes, swimming pools, spas or the sea
  • eating uncooked food, fruit or vegetables that have been contaminated (while growing or afterwards), or have been washed with contaminated water.
  • touching your mouth after handling clothing, bedding, toilets, taps, toys or nappy changing tables used by an already infected person
  • coming into contact with animals (particularly young farm animals) or soils that contain animal faeces
  • exposure to faeces through sexual contact.

Outbreaks can occur if swimming pools or local drinking water supplies have been contaminated, or through person-to-person transmission such as in a child care centre or by contact with farm animals.

Although it is less common, food handlers can contaminate cooked food if they do not wash their hands after going to the toilet.
Who is most likely to get it?

Some people are more likely to get Cryptosporidium infection, including:

  • children who are not toilet trained
  • health care and child care workers
  • animal handlers
  • international travellers, particularly to or from developing areas
  • hikers and campers
  • immunocompromised individuals.
What are the signs and symptoms?

The following signs and symptoms can occur from 2 to 10 days after exposure:

  • watery to severe diarrhoea
  • stomach cramps
  • signs of dehydration (thirst, lethargy, decreased urination)
  • nausea
  • vomiting
  • slight fever
  • weight loss.

Symptoms usually last for up to 2 weeks. It is possible for some people to recover and then suffer the symptoms again. Not everyone who carries the parasite develops the symptoms but in some cases they can pass it on to others.

For individuals with weakened immune systems, symptoms can be long lasting and at the extreme, may result in death.

How do I know I have it?

Diagnosis must be made by a medical professional. There are many causes of gastroenteritis, and laboratory testing of a faecal specimen is necessary to confirm that symptoms are due to infection with Cryptosporidium.

Cryptosporidium infection (Cryptosporidiosis) is a notifiable infectious disease (external site) in Western Australia.

How is it treated?

There is currently no cure for Cryptosporidium infection, although research is continuing. Most people who have healthy immune systems will recover without treatment.

The diarrhoea causes an excessive loss of water from the body. Infection is usually managed to prevent dehydration by ensuring that fluid intake is maintained.

Individuals with weakened immune systems are at more severe risk and should seek medical advice from their doctor early.

Avoid anti-vomiting or anti-diarrhoeal medications unless a doctor has prescribed or recommended them for you.

What should you do if you have the infection or are showing symptoms?

  • See your family doctor
  • Drink plenty of fluids such as plain water or oral rehydration drinks (available from your pharmacy).
  • Take particular care to wash your hands with soap and water before preparing food and after you have been to the toilet.
  • Do not go to work until at least 24 hours after symptoms have stopped.
  • Do not handle or prepare food until at least 24 hours after symptoms have stopped.
  • Health care workers, child care workers and food handlers should not attend work until 48 hours after symptoms have stopped.
  • Food handlers working under the Food Standards Code (external site) must follow specific requirements before resuming food handling activities. Please refer to food handlers (external site) for details.
  • Keep children home from school or child care until at least 24 hours after symptoms have stopped.
  • People in hospitals, nursing homes and other residential facilities should be nursed in their own room, with a private bathroom until at least 24 hours after symptoms have stopped.
  • Immediately remove and wash any clothes or bedding contaminated with vomit or diarrhoea using soap and hot water.
  • Thoroughly clean and disinfect contaminated surfaces with a bleach-based household cleaner immediately after any episode of vomiting.
  • Wait at least 2 weeks after symptoms have ceased before entering a swimming pool, spa, splash park, spray park or water slide.
  • Breastfed babies should continue to be breastfed throughout their illness.
How can it be prevented?

To stop the spread of infection:

  • Wash your hands with soap and water after changing nappies, going to the toilet and before preparing or handling food or drinks.
  • To wash your hands effectively, lather thoroughly with soap and running water for at least 15 seconds. Dry your hands with a clean single use towel (e.g. paper towel) and turn the tap off with the towel to avoid possible recontamination.
  • If hand washing facilities are not available then use an alcohol-based gel.
  • Supervise children to make sure they wash their hands properly.
  • Make sure foods are thoroughly cooked.
  • Wash or peel all raw vegetables and fruits before eating.
  • Do not drink undisinfected water. Be wary of private supplies after flooding or other extreme weather events, especially if the water looks turbid (cloudy).
  • Wait at least 2 weeks after symptoms have ceased before entering a swimming pool, spa, splash park, spray park or water slide.
  • Keep the water in your swimming pool or spa clean and safe by following good water treatment procedures, especially following any faecal accidents.
  • If a child in your household has Cryptosporidium infection, they should not share a bath with another child. A shower may be used rather than a bath as the risk of infection spreading through a shower is minimal.
  • Avoid unnecessary touching of farm animals, especially young calves and lambs.
  • Do not touch faeces of animals or pets without protection such as sturdy gloves.
  • Do not drink raw or unpasteurised milk.
  • If sexually active, always practice safe sex.

For travellers visiting remote areas of Australia or overseas:

  • Always make sure that your drinking water is safe to drink. If you suspect that water you need to drink may be contaminated or untreated, heat it to a rolling boil, then let it cool before drinking.
  • Remember that filtered water may not be safe. Only filters that remove objects smaller than 1 micron in size will remove Cryptosporidium.
  • Do not consume ice, or drinks prepared with or from ice, unless you know the water the ice has been made from has been properly disinfected and the ice has been hygienically stored and handled.
  • Avoid unpasteurised milk, dairy products, ice cream, salads, runny eggs, shellfish, raw food or food washed with tap water that has not been properly disinfected.
  • Only consume freshly cooked (hot) foods and beverages, bottled water from sealed containers, canned or tinned food that has been properly stored and fresh fruit and vegetables that you can peel yourself.
  • Remember – 'cook it, boil it, peel it, or leave it'.

Read more about healthy international travel.

Where to get help


  • Cryptosporidium infection (Cryptosporidiosis) is a form of gastroenteritis (gastro).
  • You can have the disease and spread it without feeling ill yourself.
  • The main symptoms are diarrhoea, stomach cramps, nausea and vomiting.
  • Good hygiene can help stop it spreading.

More information

Last reviewed: 28-11-2023

Public Health

This publication is provided for education and information purposes only. It is not a substitute for professional medical care. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your healthcare professional. Readers should note that over time currency and completeness of the information may change. All users should seek advice from a qualified healthcare professional for a diagnosis and answers to their medical questions.