There has also been a fourfold increase in the numbers of gastro causing cryptosporidiosis with 11,747 reported cases in 2024 compared with 3716 in 2023. A quarter of all cases are in children under four and most are in Queensland, possibly because the weather is warmer and people can swim most of the year.

Cryptosporidiosis is caused by microscopic parasites in the faeces of infected domestic animals, farm animals and humans. It’s spread by swimming in contaminated water, through contact with an infected person, or by drinking unpasteurised milk or dairy products. The parasite cysts (eggs) are not killed by chlorine.

You can reduce your risk of Cryptosporidium infection by:

1. Washing your hands thoroughly. Do this before handling food, after going to the toilet or changing nappies, after gardening and after touching pets and farm animals or handling their faeces/manure or, if you have been infected, for at least 48 hours after your diarrhoea has stopped.
2. Staying home.If you or your child has diarrhoea don’t go to work or send your children to school or daycare as diarrhoea is highly contagious.
3. Not swimming.Don’t enter a swimming pool or spa if you have diarrhoea or until 2 weeks after symptoms have ended. You may still be shedding cysts, which are resistant to chlorine. Don’t swim in rivers, creeks and dams during and for at least three days after heavy rain, or swim in the ocean during and at least one day after heavy rain.
4. Not preparing food for othersand not sharing towels or linen for at least 48 hours after your diarrhoea has stopped.

If you or your child have persistent gastro contact your doctor or call Health Direct.