Swimmers in NSW have been warned to stay away from beaches after heavy rain following a huge surge in diarrhoea cases.
Parents have urged to keep children with diarrhoea away from school due to soaring cases of cryptosporidiosis across the state.
Almost 500 cases of the disease have been reported in NSW since January 1, a significant increase on the five-year average of 95 cases for the same period.
Cryptosporidiosis is an intestinal infection caused by the Cryptosporidium parasite, which leads to severe diarrhoea, and is especially problematic for young children.
Health Protection NSW’s Dr. Jeremy McAnulty said that half of the cases involve children under 10 and called vigilance during swimming activities.
“The parasite survives for many days, even in chlorinated pools, and in the past very large outbreaks have been caused by people who had recently been infected going swimming,” he said via the Sydney Morning Herald. “With many schools about to hold swimming carnivals, we’re urging parents to stay alert for symptoms.”
The parasite can survive for days in chlorinated pools, posing a risk of large outbreaks at school swimming events throughout summer.
The public is advised that any water can host the parasite, but swimming pools pose a higher risk due to the parasite’s resistance to chlorine.
Recommendations include keeping children with diarrhoea at home until symptoms cease and avoiding swimming or sharing towels for at least two weeks post-recovery.
Additional precautions include avoiding swallowing water while swimming, washing hands regularly, and treating drinking water (boiling can kill the parasite).
The highest number of cryptosporidiosis cases in January were in the South Eastern Sydney, South Western Sydney, and Hunter New England health districts.
The 311 cases reported last month exceed the total of the previous four Januaries combined.
Most Sydney beaches were deemed suitable for swimming on Tuesday, with low pollution levels expected in the city’s east and north.
Heavy rain this summer has led to frequent warnings from authorities about the risks of swimming in contaminated waters.
Queensland’s cryptosporidiosis cases are even greater, with more than 823 recently recorded infections compared to January 2023’s 56 cases.
NSW Health advised that once the symptoms resolve, those with diarrhoea should also avoid sharing towels for two weeks and handling food for 48 hours. Children should also stay away from schools and areas with other kids for 24 hours after the diarrhoea has stopped.