Cryptosporidium outbreak - advice and information

Te Whatu Ora Southern (public health) has confirmed a number of local cases of illness caused by the protozoa, cryptosporidium.

There are currently (17 October) 68 cases in this outbreak confirmed by Te Whatu Ora Health New Zealand. Its investigation highlighted human faecal contamination of the water supply at QLDC’s Two Mile intake as the most likely source. Until a protozoa barrier is in place at Two Mile, a boil water notice is the most appropriate action to protect public health.

Cryptosporidium is a parasite found in the gut of animals such as cattle, sheep, cats and dogs and also birds, fish, reptiles (such as geckos and turtles) and humans. It is passed on in the faeces of infected animals and humans.

The parasites can live in the environment for long periods, especially in water in lakes, rivers, streams and roof water.

The illness caused by this parasite is called cryptosporidiosis. 

It is difficult to predict how long the boil water notice will be in place.  It will be lifted when we can be confident the water is safe to drink and the risk to the public is appropriately managed. The current best case scenario is a minimum 8 week period if a UV water treatment system can be acquired and implemented. 

Yes.  Specific testing for Crypto in the water supply is underway.   We are testing the raw water source and from with the distribution zone daily, starting Monday 18 September.  These tests take approximately three days to be returned.  

Crypto testing is not typically completed as part of routine water monitoring due to the complexities and limitations of the test. The testing is only able to tell us whether cryptosporidium was present in the particular sample of water collected and as such isolated tests do not necessarily provide a comprehensive insight of the water quality or risk.

Crypto testing is being completed at this time to help us understand more fully if there is any indication of potential protozoa contamination at the raw water source.

The water source and treatment is different for public supply schemes in Arthurs Point, Arrowtown, Lake Hayes Estate and Shotover Country. The treatment plants in these locations include ultraviolet (UV) disinfection as a protozoa treatment barrier, which is effective at inactivating cryptosprodium.    

Private schemes are also excluded from the boil water notice.

For more on this, and our district’s water supply visit our Water Supply Treatment page.

It is unlikely that you will get sick if you have already drunk the water. 

The most common symptom of crypto infection is smelly, watery diarrhoea and stomach cramps. If you live in the Queenstown area or have visited there since 18 August and are experiencing these symptoms, please call your GP and inform them.

The best thing you and your whānau can do to stop the spread of cryptosporidium (crypto) infection is to practise good hand hygiene.

This means scrubbing your hands with soap and water for at least 20 seconds and drying them thoroughly with a clean towel:

• After using the bathroom, changing a diaper, or helping others use the bathroom

• Before eating or cooking

• After handling an animal

• After gardening, even if you used gloves

• When caring for someone with diarrhoea

Other ways to help stop the spread of cryptosporidium infection are:

• Stay home or keep young children home when you or they have an active case of diarrhoea

• Don’t drink untreated water

• Clean all surfaces, including door handles, regularly with a cleaning product that contains hydrogen peroxide. Chlorine based products do not work against cryptosporidium and bleach based products are not as effective. 

• Shower before using recreational swimming facilities to wash away any potential Cryptosporidium organisms on your body.

• Don’t swallow pool water.

• Wash all produce before eating it. Peeling the skins will also reduce your risk.

• Take young children at the pool to the bathroom frequently.

• Change children’s diapers often.

• Stay clear of the water if you or your children have diarrhoea. Stay out of the water for a full two weeks after the diarrhoea subsides.

Yes. Always thoroughly wash and dry your hands. This will also help to reduce any spread of Crypto infection. You can shower but please try not to swallow the water. Please use boiled water to brush your teeth.

The Medical Officer of Health has conveyed that it is OK to use soap and town water to wash hands and make sure to dry hands properly (always good practice). The risk of infection from using the town supply water, even if it is contaminated with Cryptosporidium, is very low. 

The infectious dose is approx. 130 oocysts (https://pubmed.ncbi.nlm.nih.gov/7870140/). With soap and drying it should remove most cysts, if there are any,  on the hands from the water, if indeed it is contaminated.  It is resistant to Antibacterial Hand Gel.

The risk of not washing hands would be greater for transmission of other pathogens. 

No, please boil filtered water for one minute before using it.

Coffee machines and ice makers connected to the water supply should not be used.  Use bottled or boiled water for making coffee, ice or soda drinks. There’s further guidance on this in the ‘information for commercial operators’ section above.  

If you are a food operator affected by the boil water notice, we appreciate it is a difficult time to manage your business. Please read the ‘information for commercial operators’ section for the latest guidance.  

Please ensure your guests know the boil water notice is in place. There are downloadable resources available in the ‘links and resources’ section below.

The lap pool, leisure pool and learners pool will remain open and our usual advice is still relevant when it comes to diarrhea related illnesses - stay away from the pool for 14 days. This will help keep everyone safe!

The hot pool is open again!

We have a brief crypto update for you as we've reviewed our hot pool filtration system and we're confident that it is working correctly and continues to provide the highest level of protection possible.

In terms of keeping safe, our general information and advice around coming to the pool is as follows:

• There is no current link between crypto and the Council's water supply - all recent tests have come back clear.

• There is no current link between the crypto cases and Alpine Aqualand.

• Swim lessons for under 8s have been put on hold and we advise that children under 8, pregnant women, and the immunocompromised not use the pool while crypto is in the community.

• The only way for crypto to enter the pool is if someone has come in who has been ill or had diarrhea.

• We utilise chlorine and UV filters to disinfect the pool. Having UV filters provides a very strong level of protection against crypto but it isn't 100% guaranteed.

• We will continue to operate as normal and remind members to practice good hygiene before getting into the pool - wash your hands and shower etc.

Swimming lessons for under8s will resume from Saturday 21 October. Check out our Facebook page for updated information.

Our parks team has turned off all public drinking fountains in the affected areas.  

Public Health will be keeping the community updated on confirmed case numbers.  

QLDC will support Public Health to share information and keep you updated on the status of the water supply. 

We'll regularly review and update these FAQs and provide updates on social media, radio and via the media.