Cryptosporidium: 60 confirmed cases in Queenstown outbreak

There are now 60 cases of cryptosporidium as part of Queenstown's outbreak which began last month, Te Whatu Ora confirms.

There are also 13 probable cases and 10 under investigation.

A boil water notice remains in place.

Te Whatu Ora Medical Officer of Health Dr Susan Jack said the source of infection had not been identified but investigations were ongoing and all possibilities were being considered.

When asked if any modelling had been done including on the scale, possible sources, impact of secondary infections, spread or expected timeframe of the outbreak, Jack said no modelling has been done.

"At this stage no modelling is required, while we do a thorough investigation of possible sources," Susan Jack said.

"This includes interviewing (and also re-interviewing) all cases with a detailed questionnaire to see if any locations, food or beverage flags as a possible source of the means for transmission. We are assessing if cases are linked to each other to see if there is person-to-person spread."

The council was undertaking extensive testing of its drinking water networks and reviewing possible issues with overflow and pipes, Te Whatu Ora said.

Illnesses in the Queenstown area began to be reported on social media from early September, but cryptosporidium was only identified as the cause on 18 September.

On Monday, Taumata Arowai head of regulatory Steve Taylor told Morning Report the Queenstown Lakes District Council had been issued with a compliance order, and other councils should take note of its expectations.

The regulator had a number of options if councils did not meet the new requirements, including prosecution, Taylor said.

-This story was updated on 3 October, 2023, to add more information from Te Whatu Ora on modelling and testing.