Comment: PM's alert level 1 D-Day - why we should be there now

Derek Cheng, NZ Herald,
Publish Date
Mon, 8 Jun 2020, 9:26AM
Jacidna Ardern (Photo / Getty)
Jacidna Ardern (Photo / Getty)

Comment: PM's alert level 1 D-Day - why we should be there now

Derek Cheng, NZ Herald,
Publish Date
Mon, 8 Jun 2020, 9:26AM


Unless there is a flurry of new cases today, Prime Minister Jacinda Ardern's big D-Day decision this afternoon has already been made for her.

She has relied heavily on the advice of health chief Ashley Bloomfield, who will give the green light for a move to level 1 because of his confidence in contact-tracing capacity, border controls, ongoing surveillance testing and the trends in Covid-19 cases.

Those trends include two months since the last community transmission case of concern, 16 days of no cases to report - and 24 days since the most recent case was first reported.

On Newstalk ZB this morning, former National Party Government minister Steven Joyce said of level 1: "We should be there by now...the Government needs to get on with it."

He said the economy's capacity was being drained for "head-scratching" reasons.

He described this as a "mis-pricing of risk" and that the only measure of success could not be just how many days "you can go without a new case".

"We need the economy to be robust as soon as it possibly can and I think that's the thing missing at the moment."

There have only been 24 cases since the country moved to level 3, two since level 2 started, and none since bars were re-opened or gatherings up to 100 people were allowed.

Ardern may decide to stay in level 2 longer to see out the long tail of a possible outbreak triggered by 100-person gatherings.

But a substantial share of the general public are already in a level 1 mentality, and prolonging level 2 would risk a severe backlash.

Even public health experts - usually much more cautious than the general public - are saying that by later this week there will be a high degree of certainty that the chains of transmission have been broken.

The public health system is also well-prepared to contain new cases.

That is how Ardern has previously described elimination: the chains of transmission have been snuffed out and any new outbreak can be aggressively managed.

There was a distinct shift in language last week when Deputy Prime Minister Winston Peters talked about his wish to move to level 1.

The previous week, when he first made his view public, he said the economic benefits of level 1 outweighed the health risks.

Last week he simply stated the number of days since the last community transmission case.

That case was a Ministry for Primary Industries (MPI) worker who tested positive at Auckland Airport on April 30.

He was asymptomatic and was tested as part of the surveillance programme for essential workers at the border. He was declared well enough to come out of isolation on May 18.

This is the date that the Ministry of Health says is the starting point for the 28-day Covid-free period in its elimination strategy. Barring any new cases, that makes June 15 elimination day.

NZ First leader Winston Peters changed his language this week to focus on the public health reasons, rather than economic ones, to move to alert level 1. Photo / Mark Mitchell

But even cautious epidemiologists, including Otago University Professor Michael Baker, consider this view to be overly conservative.

How can anyone spread the virus if isolation is properly observed? Wouldn't the date of the person going into isolation be more pertinent?

Baker is among the public health experts who have questioned whether community transmission cases are the only ones to consider.

Their work marks the start of the 28-day period (they have a different range of days for different levels of elimination certainty) as the last time there was an infectious case of Covid-19 in the community.

Ardern and Bloomfield have both talked about May 22, the last time the ministry reported a case in its daily update.

That case was an Auckland woman in her 50s - the country's last remaining active case - but Bloomfield has conceded she is not in danger of infecting anyone because she was a suspected case on May 1 and has been in isolation since lockdown started in March.

That would make May 15 the starting date - a view shared by a group of six academics - which was when the most recent case was first reported - a boy aged 1 to 4 in Christchurch.

Twenty eight days from May 15 is June 11, Thursday, the day that level 1 is expected to begin if Cabinet decides today that the alert level can be eased.

It also meets Bloomfield's test of being at level 2 for at least two two-week incubation periods.

Bloomfield himself has been cautious to put a date on the 28-day Covid-free period, despite his own ministry's statement.

But he has said there have been no community transmission cases of concern for two months.

There have been 55 such cases since April 1, but lockdown and lockdown lite appear to have shut down any chains of transmission. This is backed up by the targeted testing around some of these cases which, according to Bloomfield, have not showed any onward transmission.

There cannot be 100 per cent certainty around elimination short of everyone in the country being tested at the same time, and all those tests coming back negative.

Bloomfield and Ardern have repeatedly said that elimination is not eradication. There will still be virus particles in the country and we should expect aggressive management of any inevitable new cases.

There remains a possibility, however unlikely, that a super-spreader event has taken place and it won't show up in testing data for weeks.

For example a person, unaware they had Covid-19, could have marched with the Black Lives Matter crowd in Auckland on Monday and infected a dozen people, one of whom then flew to Wellington to attend an indoor wedding this weekend, promptly infecting another dozen people.

But even if positive test results start popping up all over the country at the end of the month, our public health teams should be able to take care of it.

The contact-tracing capacity in the national centre and across 12 Public Health Units (PHUs) has gone from being able to trace 10 active cases a day to 185, with a surge capacity planned for up to 500 cases by the end of the month.

And, crucially, they are all now linked to the national IT system.

The previous system - described variously as antiquated, manual and a local cottage industry - gave the impression of someone with hand-written bits of paper tallying numbers on an abacus and then shouting daily totals to someone else at a typewriter, who then informed the ministry via morse code.

The problem was that neither the data nor the workload could be efficiently shared with the national contact-tracing centre or across PHUs in other regions.

That is no longer the case, Bloomfield insists.

Although the units in Auckland, Wellington and Christchurch still have their own IT systems, they can all interact with the national system and can work together in the event of an outbreak across multiple regions.

The remaining concern is that it has taken so long to build the new system that the ministry hasn't had a chance to test it - but Bloomfield says that will happen in coming weeks.

A bluetooth contact-tracing mechanism is also still in the works, but is not needed for a move to level 1.

Leaning on PHUs to contain an outbreak without the need to return to lockdown is how eminent epidemiologist Sir David Skegg defined elimination.

"We can all go back to normal life ... just basically forget about Covid-19. The public health service will protect us, as it does for many other diseases," he told the Epidemic Response Committee in April.

"We can stop isolating at home, people like me over 70 don't have to hide, and people can travel around the country, have holidays, you know, and get back to normality."

The ongoing global pandemic means that the new normal at level 1 will essentially be the old normal but with border controls until a vaccine is ready.

Roughly 10,000 people have come to New Zealand since a blanket quarantine was imposed from April 10.

The process appears to be watertight. Asked about the hotel, health and security staff tasked with managing these overseas arrivals, Bloomfield said not a single worker had tested positive.

But measures are still being strengthened. Work was now being done to have those arriving from overseas tested when they land, and again 14 days later.

Testing at the border, which led to the positive test of the MPI worker, will also continue.

Director general of health Ashley Bloomfield is confident in the ability of the public health units to contain any new cases. Photo / Pool

Bloomfield also wants to test and isolate all air crew flying in from Los Angeles because their movements are not as restricted as air crew flying in from Asia.

Air NZ is also testing air crew and airport staff; 30 staff have tested positive and they have all recovered.

Border controls will continually be reviewed, especially as the clamour becomes louder for transtasman travel, non-Kiwi essential workers and the return of international students.

Regardless of any economic or political reasons, there is an overwhelming case that the public health risks of moving to level 1 are very low.

It would not make sense for Bloomfield to thoroughly endorse the lines of defence that will keep Covid-19 eliminated, and then recommend a longer stay at level 2.

Ardern has previously said that Covid-19 was "currently" eliminated. That was on April 27, the day before level 3 started, when there had been a string of new daily Covid-19 cases in the single digits.

She had essentially meant at the time that the chains of transmission had been broken and any new outbreak could be aggressively managed.

That view was valid back then, and is inescapable now.

She has also said that the war against Covid-19 is a marathon, and ongoing vigilance is needed. The coming winter will make it more important to cough into your elbow, wash your hands, get tested for any sniffles, and keep tabs on who you're hanging out with.

But there is good reason to feel that the battle has been won for now and, by Thursday, the time will have come for an elimination party - with no need for any physical distancing.