What is cryptosporidiosis and how do you get it?

As Wellington grips with a gastric illness outbreak, cryptosporidiosis has reared its very spreadable head, with cases more than double the region's typical number.

Accordign to Te Whatu Ora there are now 32 cases of cryptosporidiosis in the region, with 19 of them linked to the Hutt Valley.

But what is it, what are the symptoms, and what do you do if you have it?

What is it?

Simply put, cryptosporidiosis, sometimes called crypto, is a stomach bug that can cause diarrhoea, stomach cramps, and vomiting.

It is caused by a microscopic parasite called cryptosporidium.

It can infect the gut of people, birds, and animals. It produces cysts (eggs) that can survive in the environment for a long time, such as in water in lakes, rivers, or even on the roof.

When a person, bird, or animal has cryptosporidiosis, they pass out the cysts in their faeces (poo), which can spread easily between them.

How do you get it?

Crypto is spread by hands contaminated with faeces during toilet use or nappy changing, Te Whatu Ora warns.

From hands, it can spread to surfaces, toys, food, and water. It can also spread by contact with infected animals, or in shared water such as spas, swimming pools, and baths.

You get infected when you swallow the parasites, for example, by drinking contaminated water or touching your mouth with contaminated hands, according to HealthEd.

The parasites can contaminate soil, food, or water, or surfaces such as toys, bathroom taps, or doors, and nappy change tables.

There is no way of telling by taste, sight, or smell if soil, food, water, or a surface has cryptosporidium.

The incubation period is probably 1-12 days, with an average of 7 days, according to Te Whatu Ora.

What are the symptoms?

The most common symptoms are smelly, watery diarrhoea and stomach cramps. Sometimes people:

• Have a lack of appetite
• Experience weight loss
• Have a fever.
• Feel sick (nausea) and throw up (vomit).

Symptoms for most people will stop within a few days to a week. In the meantime, it is crucial to stay hydrated.

If symptoms persist for longer than a week, or you are concerned, you should contact your health provider or Healthline.

Symptoms are not typically severe or long-lasting, but those without can still pass on the eggs through their faeces.

What should you do if you have it?

Most people with cryptosporidiosis get better without treatment, but you should still take extra care, Te Whatu Ora warns:

• Ensure you drink plenty of fluids. This is especially important for sick children as they become dehydrated easily
• Do not return to work, school or pre-school until free of symptoms for 48 hours. This includes food-handlers, early childhood workers and healthcare workers
• Do not use swimming pools, hot tubs, or splash pads for at least two weeks after your symptoms stop
• Avoid visiting people in hospital or long-term care facilities for at least 48 hours after your symptoms stop
• Wash hands regularly with soap and hot water especially after visiting the toilet. Dry hands thoroughly after washing
• If possible, do not prepare food for anyone else until 48 hours after your symptoms stop
• Disinfect toilets regularly
• Use your own towel; do not share with anyone else
• Bathe separately or bathe sick children after others.

People with weakened immune systems should do the same, but are told to contact their medical or healthcare provider if they are concerned.

Previous outbreaks in New Zealand

Wellington is currently experiencing an outbreak of cryptosporidiosis, with 32 cases in the region.

The gastric illness has been connected to swimming pools, with 19 of them linked to the Hutt Valley.

The number of cases is more than double than what the region typically experiences, with fears that it has spread even further due to lower reporting.

National Public Health Service medical health officer Dr Craig Thornley said 16 of the cases have either used swimming pools themselves or lived with a household contact that used a swimming pool before they became sick.

The cases come after Queenstown had its first gastro outbreak in 40 years in 2023, with 72 confirmed cases of cryptosporidiosis.

A boil water notice was issued as a result, as the local council sought to protect the water supply from further spreading.

Queenstown Lakes District Council (QLDC) also installed UV treatment at its Two-Mile treatment plant, as well as bringing plants without the necessary protections up to compliance, and cleaned the entire network supplied by the plant.

Te Whatu Ora said the source of the cryptosporidium outbreak in Queenstown was most likely human faecal contamination of the water supply.

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