Cryptosporidiosis

The most common symptom is diarrhoea, which is usually watery and may be profuse. The diarrhoea is associated with cramping abdominal pain. Other symptoms include nausea, vomiting, fever, headache, and loss of appetite. Some people infected with Cryptosporidium may not develop any symptoms.

In healthy children and adults, the illness typically resolves without any specific treatment. Symptoms may last from days to weeks. People with weakened immune systems may not clear the parasite and the illness may persist for longer.

There is no specific treatment for cryptosporidiosis. People should ensure they have adequate fluid intake when they have crypto, especially over the summer months when crypto is more common. Persons with severe illness, difficulty in maintaining an adequate fluid intake or having long lasting diarrhoea should seek medical advice.

Cryptosporidium is shed in the faeces of infected humans and animals from the onset of symptoms and may continue to be shed in the faeces for several weeks after symptoms have stopped. The infectious agent is a hardy, thick-walled cyst called an "oocyst". The oocyst can survive in a moist environment for up to 6 months. It may then be transferred to humans when people accidentally swallow the parasite, in one of several ways:

• person-to-person spread, especially in households and childcare settings
• handling of infected pets, farm animals, or their faeces
• food and water contaminated by the faeces of infected animals or persons. This includes swallowing contaminated recreational water, for example in swimming pools, splash parks and dams
• exposure to faeces during sexual activities.

Cryptosporidium is resistant to the usual levels of chlorine in swimming pools and may survive for days in pools. High doses of chlorine and cleaning of filters can remove Cryptosporidium from a contaminated pool. Oocysts are sensitive to hydrogen peroxide, ozone and ultraviolet radiation.

The time from contact with the parasite to development of symptoms is usually about 7 days but can be longer.

Practicing good personal hygiene can reduce the chances of getting cryptosporidiosis.

Children with diarrhoea should not return to childcare or school for at least 24 hours after the last episode of diarrhoea. Food handlers and health care workers should remain away from work for at least 48 hours after the last episode of diarrhoea and be vigilant with hand hygiene.

As people with cryptosporidiosis can remain infectious even after symptoms have settled, they should not go swimming while they have diarrhoea and for two weeks after diarrhoea has stopped.

There is no vaccine to prevent cryptosporidiosis and no way of preventing the illness in people who have been exposed.

There are numerous ways to prevent exposure to crypto, including:

• washing hands thoroughly after using the toilet, changing nappies and before handling food or eating (including after swimming)
• washing the hands of toddlers and babies after a nappy change
• washing hands after contact with pets, and after cleaning up animal faeces
• washing hands after gardening or other direct contact with soil
• washing hands after contact with cattle and other farm animals
• washing fruit and vegetables before eating them
• not eating or drinking unpasteurized milk products
• not drinking untreated water and inadequately filtered water and boiling untreated water or water of unknown quality for at least one minute before drinking
• not swallowing water in swimming pools or other recreational bodies of water
• showering before and after swimming in pools and splash parks
• avoid swimming in natural waters (rivers, creeks, dams, surf) within a week after heavy periods of rain
• not sharing linen and towels while diarrhoea is present and for 2 weeks after diarrhoea has stopped.

People with weakened immune systems may need to take special precautions to reduce their risk.

For further information, please contact your local doctor, health centre or nearest public health unit; or call 13 HEALTH (13 43 25 84) 24 hours a day 7 days a week for the cost of a local call.

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