Giardia is a parasite that can give you diarrhoea and sometimes make you feel very sick.

The parasite is found in the gut of infected people and animals. It is passed on in the poo (faeces) of infected humans and animals. People become infected when they swallow the parasites, usually in contaminated water.

People with giardia may experience diarrhoea, stomach cramps and vomiting.

If you are concerned about giardia, call Healthline on 0800 611 116 or see your doctor or practice nurse.

You get infected when you swallow the parasites, for example, by drinking contaminated water or touching your mouth with contaminated hands.

People or animals who have giardia pass on the parasites in their faeces.

The parasites can contaminate soil, food or water, or surfaces such as toys, bathroom taps or doors, and nappy change tables.

The parasites can live in the environment for long periods, especially in lakes, rivers, streams and roof water. There is no way of telling by taste, sight or smell if soil, food, water or a surface has giardia.

Giardia symptoms include:

  • diarrhoea
  • stomach pains
  • feeling sick
  • vomiting

Symptoms can appear three to 25 days after you become infected. You can be ill for three to four days, then feel better, then the symptoms may come back. 

If you think you have giardia see your doctor or call Healthline on 0800 611 116. They will probably ask you to provide a stool (poo) specimen for testing. People with giardia can be treated with antibiotics.

Stay away from school, early childhood centres or work until two days after the symptoms have gone.

Giardia is a notifiable disease. This means that health professionals or laboratories will inform us when someone has it. This allows us to monitor the number of people who have the disease and give health professionals advice on how to reduce its spread. 


There are specific requirements for notifiable diseases in the Auckland region.

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Last updated 22.11.2022

For health advice call Healthline for free anytime on 0800 611 116
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