Coronavirus: The considerations behind Prime Minister Jacinda Ardern's COVID-19 alert level decision

It's decision day - Jacinda Ardern will at 3pm reveal if the entire country will remain under lockdown or if restrictions in some places will be lifted, leaving Auckland and Coromandel to go it alone. 

Cabinet is meeting at 1pm to discuss the factors that will influence the decision. They'll be looking at testing rates, the number of active cases, how far the current outbreak has spread, and whether rules have been followed. 

So far compliance has generally been good, according to Director-General of Health Dr Ashley Bloomfield. Police revealed there have been more than 600 reports of lockdown breaches, but the "vast majority" have been compliant. 

Testing numbers are looking good too. On Wednesday, the first day of lockdown, testing centres in Auckland had their busiest day since the August outbreak last year - almost 16,000, while 12,885 were processed across the country.

The number of tests processed across the country on Thursday was 27,899. Testing centres in Auckland had their busiest day ever, by more than 50 percent.

The cluster of confirmed COVID-19 cases in the community currently sits at 31 across Auckland and Wellington - 19 connected to the first case, a Devonport man in his 50s. The rest are under investigation.

An Air New Zealand worker in her 60s tested positive after travelling from Japan, but she is not connected to the cluster. 

What's most promising is that there's a better understanding now of how the virus got into the country. We knew it came from the New South Wales outbreak across the ditch, and now we know it's linked to managed isolation.

"I know everyone outside Auckland and the Coromandel is anxiously awaiting news on how long their level four conditions will remain in place," Prime Minister Jacinda Ardern said on Thursday.

"Ministers will meet tomorrow morning and will share a decision at tomorrow's update... We believe we now have a good handle on the how and where."

That said, Delta is tougher than previous variants of COVID-19, so while the Government has further information to inform a response, Ardern said it will be a "a tough fight" that everyone will need to participate in. 

Prime Minister Jacinda Ardern.
Prime Minister Jacinda Ardern. Photo credit: Getty Images

"We've already given the indication to Auckland and Coromandel around what we believe our intention will be, for level four over the seven day period. We already gave that indication from the beginning." 

Ardern said Cabinet will be looking at "the degree to which we believe we have a ring around the outbreak".

"What we're always looking for is whether or not the positive cases that you've got coming through are from those that you are deliberately identifying as contacts and then testing, as opposed to people we have not yet identified. That's one of the things we look for.

"At the moment the cases we're tracing have an infectious period across the period pre-lockdown. The period of time you spend in lockdown reduces that and of course that puts you in a much better position."

And then there's the spread. 

"We want to see a high number of testing across other parts of the country, so if you're symptomatic and you live outside Auckland and Coromandel, we particularly want you to go and get tested. That lifts our confidence that we haven't got spread."

More than a thousand contacts have been identified, with more than 140 locations of interest identified including schools, which will no doubt play into the Government's decision-making. 

Case origin revelations

Ardern revealed that genome sequencing of current cases matches that of a recent returnee from Sydney who arrived on a red zone flight - a direct flight from New South Wales to quarantine in New Zealand - on August 7.

The individual was tested the following day on August 8 and returned a positive test result on August 9. They were transferred from the Crowne Plaza managed isolation facility to the Jet Park quarantine site that same day. 

This person became unwell and was moved to Middlemore Hospital on August 16. But the hospital is not a line of investigation because the individual was only moved there on August 16, one day before the lockdown and days after the current cases experienced symptoms. 

"What this information tells us is that our cases are most likely to have come from the traveller. This is a significant development," Ardern said.

"It means now we can be fairly certain how and when the virus entered the country and that based on timelines there are minimal, possibly only one or maybe two, missing links between this returnee and cases in our current outbreak, and the period in which cases were in the community is relatively short."

Auckland Airport and Customs were asked to investigate any contact the positive case may have had with staff when they got off the plane, but nothing has been picked up to date. 

That means it could have been a breach at the Crowne Plaza or Jet Park facilities. 

The traveller from Sydney was transferred to the Jet Park quarantine facility.
The traveller from Sydney was transferred to the Jet Park quarantine facility. Photo credit: Google

Of the 208 staff who worked at the Crowne Plaza where the positive case was, only one staff member is overdue for testing and only by less than 48 hours. At Jet Park, two out of 200 staff are overdue tests, but again by less than 48 hours. 

All staff are being re-tested. 

It's since been revealed a family staying adjacent to the case at the Crowne Plaza tested positive for COVID-19 on day 12 of their stay. 

It's reminiscent of the findings of a recent investigation at Jet Park, which found that COVID-19 transmission at the facility was likely caused by room doors being opened simultaneously for just seconds at the same time. 

It shows just how transmissible the virus is. 

"Everyone at the moment is really focussing in on the Crowne Plaza, just as a result of timing. There's no other reason really more than the timing of the onset in some of the other cases we've seen," Ardern said. 

"At this point in time though, I don't have a working theory. We are chasing down every possible point at which this individual had contact with others and just seeing if we can analyse every single element."