A worrying rise in the number of Cryptosporidiosis cases in New South Wales (NSW) and Queensland has prompted health officials to warn people who have suffered from diarrhoea not to go swimming for at least two weeks afterwards, to prevent spreading the parasite.
NSW has seen 498 reported cases of cryptosporidiosis so far this year compared to the usual five-year average of 95.
Queensland’s case numbers are even higher, with more than 823 infections compared to just 56 cases in January 2023.
The disease is caused by a parasite that infects the intestine, and commonly causes watery diarrhoea and stomach cramps. Occasional symptoms include fever, nausea, vomiting, and loss of appetite.
It is a common cause of acute diarrhoea in young children, particularly those aged under ten. Children in that age group have accounted for almost half of the cases in NSW.
Parasite Survives for Days
NSW Executive Director of Health Protection, Dr. Jeremy McAnulty, explained that people typically get the disease by swimming in and then swallowing water containing the parasites, called Cryptosporidium.
“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.
He urged people who have had diarrhoea not to go swimming for at least two weeks afterwards.
“Almost half of the cases reported this year had been swimming during their exposure period, and with such a high proportion of young children affected and with many schools about to hold swimming carnivals, we’re urging parents to stay alert for symptoms,” Dr. McAnulty said.
Complicating matters is the fact that symptoms of Cryptosporidiosis generally begin two to 10 days, with an average of seven days, after becoming infected with the parasite, and some people will have no symptoms at all, according to the U.S. Centers for Disease Control and Prevention(CDC).
NSW Health advises that once the symptoms have cleared, people should still avoid sharing towels for two weeks and handling food for 48 hours. Children who have diarrhoea should be kept home from preschool, childcare, or playgroup until 24 hours after the diarrhoea has completely stopped.
To avoid catching the disease, people should wash their hands thoroughly and regularly, avoid swallowing water, and avoid swimming in waterways and beaches after heavy rain.
Victoria has also experienced a recent surge in Cryptosporidiosis since the beginning of September 2023, and issued a health alert in December. Several European countries and New Zealand have also reported a recent increase in the number of cases.
Cryptosporidiosis cases typically surge during warmer months when more people are swimming and using public pools. The Cryptosporidium parasites, known for causing this disease, exhibit high resistance to chlorine levels commonly found in swimming pools.
Boiling water is a method of effectively killing the Cryptosporidium parasite.
