Ninety seven per cent of staff working in managed isolation facilities and quarantine hotels were tested last week and no-one tested positive for Covid-19.
The next round of testing of MIQ testing is currently underway, Minister for Managed Isolation and Quarantine Megan Woods said, and would be completed by September 6.
Regular testing of border-facing workers would commence in the weeks.
The Government has brought in Sir Brian Roche and Heather Simpson to ensure the testing strategy is being properly rolled out, after the Ministry of Health's response had been too slow.
Testing these workers is considered an extra layer of defence, as it could uncover an undetected branch of Covid-19 transmission early.
Air Commodore Darryn Webb said a new positive case in Wellington flew in from Los Angeles, and the facility in Wellington was also set up to quarantine Covid-positive people.
Woods said travellers take a chartered flight to Wellington, so there is no mixing with the general public.
Webb said sometimes people fly into Auckland and then flown to another location where they are then tested.
Woods said the Government was looking at how to further open up the border, and who to prioritise. It was an active work programme with ministers.
Auckland cluster and the Rydges maintenance worker
Woods said that the current cluster does not seem to have come from an MIQ facility, based on the genomic sequencing results so far.
She said the Rydges maintenance worker case had been closed and it's most likely that he caught Covid-19 from using the elevator at the hotel shortly after a Covid-positive case had used it.
Webb said cleaning protocols had been improved to make the facilities as safe as they can be.
"Hand sanitiser is an absolute key requirement and used every time someone uses a lift."
Woods said there was a two-minute interval between them using the lift.
Woods said when she took over the responsibility for MIQ, capacity was at its limit and people were moved to different cities in the middle of their isolation period.
But capacity now had breathing room and that was no longer taking place.
The origin of the current outbreak has not been determined, but it is thought to have come through travellers at the border, given that it's unlikely to have come from freight surfaces.
Woods said the MIQ allocation system - ensuring there is a place in a hotel before people are allowed to buy a flight home - was being rolled out and was expected in the coming weeks.
She didn't have details on how many people have had to pay for a MIQ stay so far.
Having a purpose-built facility for MIQ was something the Government had considered from the beginning of the response, Woods said.
"What we need to do is have a look at how that stacks up in terms of the cost of construction and the cost of running it compared to leasing hotels at the moment."
Day three tests
Asked why day three testing wasn't made mandatory, she said "we're willing to evolve" and it could be changed if health officials deemed it necessary.
She said making it mandatory would be "more important" if there had been any transmission from an MIQ facility - which there has not been any evidence of.
From July 18 to August 24, 97 per cent of people were tested on day 12 and 95 per cent of people were tested on day three.
Woods said there were a number of reasons why day three tests weren't completed, including if they were a child under six months' old, or refusal of testing, or for medical reasons.
She said day three tests were not compulsory but were being done in "high numbers nonetheless".
Fifteen people have refused a day 12 test so far. They all eventually decided to be tested, Woods said.
Webb said 108 of the 500 extra Defence Force personnel were already in place, and more would be rolled out weekly.
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There were 5018 people were staying at 32 managed isolation and quarantine (MIQ) facilities across the country as of midnight last night.
Woods has also announced that all workers in MIQ facilities will trial the CovidCard, which records other CovidCard-carrying contacts in close proximity.
This could also help ring-fence an outbreak quickly if a new outbreak started from a traveller carrying Covid-19 and coming into New Zealand.
This morning Trade Me founder Sam Morgan said his CovidCard team had disbanded.
"The CovidCard Team - the private sector people - have all stood down from any involvement because we see no pathway to success in the way this is being done," Morgan told the Herald.
He said the team had forwarded hundreds of pages of technical information to the Health Ministry after the Nelson trial in May and was standing by ready to assist.
But nothing happened, and Morgan has become frustrated in the months since.
"There is no capability or commitment within the Ministry of Health to do it," he added.
"There is, in fact, active resistance and has been since we began."
A ministry spokesman told the Herald: "The CovidCard trial is partway through the design phase. We expect to complete the trial around the end of September, with a report to Cabinet by the end of October.
"The Rotorua trial will help us determine whether the CovidCard works in a real-world scenario and will also allow us to test public sentiment.
"We expect a decision on whether to deploy the CovidCard more widely will be made before the end of the year."
Morgan, who sees the CovidCard replacing an app and having 80 per cent plus adoption for effectiveness, responded: "There is no chance they can deliver even a trial in the timeframe they've given."
He added: "Deployment to managed isolation facilities might yet be possible because MoH are not involved - that is being driven out of MBIE under Minister Megan Woods."
Woods said the CovidCard trial for MIQ workers and overseas returnees was still being worked through.
That trial was gong to start in three to four weeks, Webb said.
Woods added that they were exploring using CovidCards in places like lifts to provide more information about who might have been where in an MIQ facility.