What is it?

Giardia is a tiny parasite (only about 1/100th of a millimetre) that causes diarrhoea (runny poos) by infecting the intestines of humans and some other mammals. It doesn’t breed outside of the intestine, but has a cyst stage, like a tiny egg, that can survive on toys or other surfaces or in water for days or weeks. Giardia cysts live longer if they stay moist.

Giardia infection causes diarrhoea, abdominal cramps, smelly loose bowel motions and flatulence. It can also cause vomiting. Giardia infections can last for weeks or months, and can cause weight loss if not treated. Sometimes people (especially children) can have giardia infections without symptoms.

Symptoms appear between 3 – 25 days (usually 7 – 10 days) after becoming infected.

How does it spread?

Giardia is excreted in poos, a person with a giardia infection can pass 100 million cysts in one bowel motion. It is usually spread in early childhood centre environments by contamination of hands, toys and other surfaces or objects after toilet use or nappy changing. Food and water can be contaminated by hands.

You can catch giardia from contaminated water, for example from a stream, contact with infected animals such as cats, dogs, cattle and possums.

Exclusion period

A child or teacher with giardia needs to stay home until they have been free of symptoms for at least 48 hours.

Responsibilities of staff

  • Tell parents that a child at the centre has giardia.
  • Display information about giardia on your notice board.
  • Make sure all teachers, children and babies wash and dry their hands thoroughly after nappy change, toileting and before eating or handling food and infant formula bottles. Uncooked foods such as fruit, crackers etc. can easily become contaminated by unwashed hands.
  • Make sure that children wash their hands after nappy change, and help children who cannot wash their hands properly.
  • Wash all toys and surfaces with hot soapy water, and then disinfect with 1:10 dilute bleach (1 teaspoon bleach to 500ml water).
  • Wash smaller toys in the dishwasher.
  • Remove play-dough, art and water-play until there are no more cases of giardia.
  • If you are cleaning up vomit or poos use 1:10 bleach, wear a mask, apron and gloves. Be aware of what you touch when wearing gloves to avoid contaminating the surrounding area.

Responsibilities of parents

  • Keep your child home until they have been free of symptoms for at least 48 hours.
  • Make sure all family members are washing and drying their hands. Use liquid soap and dry them thoroughly.
  • The child with giardia should not share towels with the rest of the family.


There is antibiotic treatment available for giardia from your doctor.


Download printable factsheet

Last updated 14 July 2022.