The public health team investigating Queenstown’s cryptosporidium outbreak is increasing its focus on sources of infection other than widespread contamination of the water supply.

Te Whatu Ora is working alongside Queenstown Lakes District Council (QLDC) to establish the source of the outbreak. 

Attention initially focused on Queenstown’s water supply after water regulator Taumata Arowai served a compliance order on QLDC for its Two Mile water treatment plant which serves much of the Whakatipu Basin. The plant does not have a protozoa barrier to stop the parasite cryptosporidium from entering the water supply.

Read more: Queenstown parasite outbreak raises concerns about Upper Clutha water supplies

Medical Officer of Health Dr Emma Sherwood said determining the source of any cryptosporidium infection is a complex and difficult task because it can be spread in so many different ways.

“The standard potential sources of contamination include from people who have recently travelled overseas, food or drink products, hospitality premises, recreational water, or water that’s been tainted by parasites from animals – that’s a huge pool of potential sources of infection.

“Our team is keeping an open mind and looking at each and every possibility. We are not confining the source investigation to just the local water supply,” she said.

A joint agency incident management team has been working on the response since being stood up last Tuesday (September 19) and health protection officers from Southern with support across the South Island have been interviewing positive cases to determine any links between positive cases, or potential contamination sources in common.

They have also been investigating practices at hospitality businesses and those producing food and using water in manufacturing processes.

Te Whatu Ora incident controller Lynette Finnie said the team is actively working on establishing the size of the outbreak and trying to see if it is concentrated in a particular area.

“A heat map of positive cases’ places of residence and work shows most are from the CBD area,” she said.

“We’re leaving no stone unturned – we want to get to the bottom of this as quickly as possible. We acknowledge this is a massive inconvenience to the public, businesses and the hospitality and tourism industries.”

By yesterday morning there were 30 confirmed cases of cryptosporidium, as well as nine probable cases and seven cases under investigation.

One person was hospitalised due to complications from crypto. They have since been discharged. 

PHOTO: Supplied