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Page last updated on 28 February 2019

Cryptosporidiosis is the illness caused by infection with the parasite Cryptosporidium. It causes a gastroenteritis that presents as watery diarrhoea, but 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 humans, pets, wild and farm animals and the infection 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 cruises and the like, is very 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 hand that comes into contact with the parasite after touching surfaces (e.g. nappies, 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 travellers. As you can imagine, when you’re feeling unwell and experiencing diarrhoea, you may not realise when you 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 or your travel companions 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 resolve 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 of cryptosporidium and its prevention, speak with your healthcare professional.

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Sources & Citations

  1. Victoria State Government. Better Health Channel. Gastroenteritis - cryptosporidiosis. Available at: (accessed 25 October 2018).
  2. Centers for Disease Control and Prevention. Sources of infection and risk factors. Cryptosporidium. Available at: (accessed 25 October 2018).

SPANZ.SAPAS.18.10.0375 - Date of preparation October 2018