Cryptosporidiosis cases on the rise

Queensland health authorities have reported a rise in cryptosporidiosis cases, with more than 823 cases since the start of 2024.

The gastrointestinal disease caused by the microscopic parasite Cryptosporidium is a common cause of acute diarrhoea in young children. As well as infecting humans, Cryptosporidium occurs in a variety of animals including cattle, sheep, dogs and cats, said Queensland Health in a statement.

The state reported a total of 736 cases in January 2024 alone — which is 13 times higher than the numbers reported in January 2023 (56), and which surpasses the annual totals for both 2021 (569) and 2022 (568).

“Children aged nine years and under account for 39% of the 736 notifications in January 2024. A further 24% of notifications were in the 30–39 years age group,” the statement said.

The rise in cases is not unique to Queensland, with New South Wales and Victoria also reporting similar increases in cryptosporidiosis notifications in recent weeks, the statement said.

Victoria saw an increase in cryptosporidiosis cases since the beginning of September 2023, with some cases linked to swimming in public pools, according to a health alert issued by the Victorian Department of Health in December 2023. Several European countries and New Zealand have also reported a recent increase in the number of cases.

Queensland Chief Health Officer Dr John Gerrard said Cryptosporidium was usually acquired through the ingestion of contaminated water or food, or through contact with infected individuals or animals.

The most common symptom of cryptosporidiosis is diarrhoea, especially in young children. Other symptoms include nausea, vomiting, fever, headache and loss of appetite.

“Drinking or accidentally swallowing water contaminated with Cryptosporidium parasites is a common mode of transmission. This can occur in various settings including swimming pools, water parks and other recreational water facilities where water may be contaminated with faecal matter,” Gerrard said.

“To prevent spreading the infection, people with cryptosporidiosis should avoid swimming in pools, water parks or other recreational water facilities for at least 14 days after diarrhoea has ceased.”

“It’s important to wash hands thoroughly after going to the toilet, changing nappies and after cleaning up animal faeces to minimise transmission of disease,” Gerrard said.

People can also minimise risk by washing fruit and vegetables before eating them, boiling any untreated water and then cooling it before drinking, and avoiding swimming in rivers, creeks or dams within a week after heavy rain, Gerrard said.

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