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Disease

Cryptosporidium

Page last updated on 14 June 2022

Cryptosporidiosis is the illness caused by infection with the parasite Cryptosporidium. It causes gastroenteritis with  watery diarrhoea, and can be quite serious for people with weakened immune systems.

Key disease information

What is cryptosporidium?

Cryptosporidium is a protozoan parasite – a single-celled organism that causes gastroenteritis (or gastro). The parasite lives in the bowel of infected humans, pets, wild and farm animals and causes diarrhoea, stomach cramps, fever and vomiting, which can last for several weeks

How is cryptosporidium spread?

Cryptosporidium is spread by ingesting the parasite from contaminated food, fluids or surfaces. When you are travelling, particularly on cruise ships, where many people use the same facilities, cryptosporidium would be easily spread if an infected person isn’t careful about their hygiene. An infected person can shed millions of parasites in their faeces, and these can make their way into food and swimming pools if not careful. 

It can also be contracted after touching your mouth with your hand if it has come into contact with a contaminated object or surface (for example, nappies from an infected infant, or while caring for an infected person). So if you or your travel companions are unwell, it is best to avoid others as much as possible. Even if you are not on a boat, cryptosporidium can be a threat for adventurous travellers who might consider drinking from lakes or streams. Beware - animals can also contract cryptosporidium and contaminate lakes and other untreated water sources.

Is cryptosporidium contagious?

Yes, cryptosporidium is highly contagious and spreads easily from an infected person (who sheds millions of parasites in their faeces). Therefore, any slip up in proper hygiene or food preparation practices can transmit the parasite to unsuspecting others. People who are feeling unwell and experiencing diarrhoea, you may not realise that they are contaminating surfaces and putting others at risk.

For those who like to get out amongst nature, cryptosporidium can still be a problem. It’s not just people who spread the disease – animals can too. It can also be contracted by drinking from untreated water sources like lakes or streams where infected animals may have contaminated them. Therefore you should think twice before filling up that water bottle on a hike through the forest.

If you are unwell, consider others and avoid public areas as much as possible. Also, avoid entering swimming pools or spas for at least two weeks after symptoms of the disease have stopped to make sure you don’t pose a risk to others.

What are the symptoms of cryptosporidium?

The symptoms of cryptosporidium appear around one to 12 days after infection and may include:

  • Watery diarrhoea
  • Abdominal cramps
  • Bloating
  • Vomiting
  • Fever.

While symptoms last around 1-3 weeks in most people, it can be a serious illness for people with weakened immune systems.

How can cryptosporidium be prevented?

The best ways to prevent infection are:

  • Keep away from public areas until their diarrhoea has stopped.
  • Wash hands properly, especially after using the toilet and handling animals.
  • Use paper towels when drying hands. This is important for food handlers.
  • Avoid preparing food and touching communal food items or utensils until symptoms have stopped.
  • Do not swim in pools or lakes for two weeks after diarrhoea has stopped.
  • Clean bathrooms and other surfaces regularly.
  • Filter or boil contaminated water before drinking.

For more information on cryptosporidium and its prevention, speak with your healthcare professional.

Vaccine Hub offers general information only. Please see a healthcare professional for medical advice

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Sources & Citations

  1. NSW Government Health. Cryptosporidiosis Communicable Diseases Factsheet. Available at: https://www.health.nsw.gov.au/Infectious/factsheets/Factsheets/cryptosporidiosis.pdf (accessed June 2022).
  2. Victoria State Government health.vic. Cryptosporisiosis. Available at: https://www2.health.vic.gov.au/public-health/infectious-diseases/disease-information-advice/cryptosporidiosis (accessed June 2022).
  3. Better Health Channel. Gastroenteritis – cryptosporidiosis. Available at: https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/gastroenteritis-cryptosporidiosis?viewAsPdf=true (accessed June 2022).
  4. Centers for Disease Control and Prevention. Parasites – Cryptosporidium (also known as “Crypto”). Sources of Infection & Risk Factors. https://www.cdc.gov/parasites/crypto/infection-sources.html (accessed June 2022)

MAT-AU-2201782   Date of preparation June 2022