Covid-19

Long read: The month that changed New Zealand

Analysis: In just 24 days, New Zealand went from its first case of Covid-19 to a nationwide lockdown. Using new documents proactively released by the Government, Marc Daalder explores how and why that happened.

On February 27, as Cabinet mulled a possible exemption to border restrictions for international students it noted "the situation globally is changing rapidly and the risk of a confirmed case in New Zealand is high".

What it didn't know is there were already three Covid-19 cases in the country.

One, a woman in her 60s who had the day before returned from Iran, was already being cared for in Auckland Hospital, awaiting a test result that would prove what doctors already suspected: She was the country's first case of the novel coronavirus.

Two others, a couple, had arrived in New Zealand the same day as the first case, travelling from northern Italy via Singapore. They too would come down with illness and would test positive in the next few days, becoming the country's second and fourth cases.

At Cabinet on the 27th, as ministers digested the Ministry of Health's 28-page briefing opposing exceptions for international students, Health Minister David Clark told them what he could about the woman from Iran.

She was, Cabinet minutes note, "a suspected case of Covid-19 in New Zealand, and [...] test results will be known on Friday afternoon, 28 February 2020. The Ministry of Health will be considering the next steps in respect of this case on Friday morning".

In the meantime, Cabinet imposed new travel restrictions on Iran and instructed Immigration Minister Iain Lees-Galloway to investigate "whether there should also be restrictions on persons travelling from Italy and South Korea, particularly from the Daegu area, and to report back to [an informal Cabinet committee created to deal with Covid-19] the group of Ministers with Power to Act as soon as possible".

Over the next four weeks, New Zealand would change into a different country. Just 28 days after the country's first Covid-19 case was announced, New Zealand had entered a lockdown it would not emerge from for seven weeks.

Cabinet documents released by the Government charting the country's health response from February through mid-April allow the public to see, for the first time, a complete picture of the month that changed New Zealand.

Cases trickle in

By late February, it was apparent that the new coronavirus, now known as SARS-CoV-2, was no laughing matter.

There were more than 80,000 cases worldwide and more than 2800 deaths - three-and-a-half times the death toll of the 2003 SARS outbreak.

All but a handful of these, however, were in China - largely in the country's Hubei province and the logistics hub of Wuhan.

Nonetheless, Cabinet on January 31 authorised making the novel coronavirus a notifiable disease under the Health Act 1956, allowing Medical Officers of Health to surveil for and manage the virus.

A month later, at 6.30pm on February 28, Clark stood up before an audience of reporters in the Ministry of Health's Wellington headquarters and informed the nation that the coronavirus had arrived on New Zealand shores.

"You will now have learned that New Zealand has become the 48th country to identify a case of Covid-19," he told the nation.

The next day, the front page of the New Zealand Herald declared "Pandemonium" in a bold-type headline above a picture - from Tehran - of health officials in hazmat suits disinfecting a train.

Despite the panic-buying that followed, there was little urgency in Cabinet, which wouldn't make another health-related decision - other than the official formation of a Cabinet committee to deal with the virus - until March 9.

The restrictions at the border were reviewed every 48 hours during this period. On February 28, Director-General of Health Ashley Bloomfield outlined the reasons why some countries were subject to total travel bans while others were just being monitored.

Border decisions were based, Bloomfield wrote in a paper, on "growth in cases", "health system capability/public health containment measures" and how other countries - particularly Australia - were responding.

Italy, Japan, Hong Kong, South Korea, Singapore and Thailand were all considered "Category Two" areas, which "will be monitored on a continual basis and people who have travelled from or via Category Two areas will be advised to seek medical advice if they develop symptoms of fever, cough or shortness of breath". Hard restrictions were only in place against China, Iran and the Diamond Princess cruise ship.

The March 1 review recommended these arrangements remain in place, even as case numbers in Korea jumped by more than a third in 24 hours. The next day, however, Cabinet devised a new system under which "Category 1A" countries were subject to total travel bans while people travelling from "Category 1B" countries - now South Korea and northern Italy - had to self-isolate for 14 days after arrival.

On March 4, Bloomfield announced New Zealand's second case of Covid-19. Three more would follow in short succession - a person recently arrived from Iran, then the second case's partner, then the third case's partner.

Situation overseas worsens

By March 9, the situation was worrying enough that Cabinet made Covid-19 a quarantinable disease, allowing the Prime Minister to issue an epidemic notice if needed and providing the legal framework for quarantining of sick passengers at the border.

Overseas, the virus was beginning to take a serious toll outside of China. The death toll in the United States had swelled to 22, just 10 days after the first death.

In a matter of days, satellite footage would reveal mass graves in Iran, each systematically filled over the coming hours and days.

In Lombardy, Italy, doctors had begun to apply a system to help them decide who would receive treatment and who would be left to die, as the region ran out of ventilators and medical staff fell ill.

The number of countries with at least one confirmed case had doubled since New Zealand's first case.

As a signal of the economic damage to come, the Dow Jones Industrial Average dropped 2000 points on March 9 - a record that would be surpassed twice in the next week.

New Zealand also began to take the threat more seriously over the next week. With five imported cases, it became clear that the first stage of the Influenza Pandemic Plan (IPP) that the Government was using - "keep it out" - was not guaranteed to succeed.

A paper from the All of Government Controller John Ombler addressing "critical issues and areas of focus" noted the likelihood that New Zealand would move to successive stages. The IPP has five stages: keep it out, stamp it out, manage it, manage it (post-peak) and recover from it.

Newsroom has previously reported on how the IPP was, in the words of epidemiologist Michael Baker, "a good plan for the wrong virus". It deprioritised measures that would prove crucial in fighting Covid-19, including contact tracing and border restrictions. The plan doesn't mention anywhere the possibility of closing the borders to all non-residents.

Because pandemic influenza spreads so quickly, contact tracing is unlikely to isolate infected people before they infect others. Containing or eliminating pandemic influenza is virtually impossible - most countries come to the conclusion that they have to manage it as best they can.

But SARS-CoV-2 isn't an influenza. With a longer incubation period - about double that of pandemic influenza, on average - it can be stopped in its tracks with effective contact tracing. Nonetheless, Ombler's paper shows the Government had paid little attention to the second step of the IPP.

One of the key decision points would be "deciding to move from Keep It Out to Manage It, while noting that some regions may be in different phases. This will require decisions around the extent and nature of border measures (entry and exit) [and] containment efforts including contact tracing."

"Managing and slowing the spread will require taking decisions on: cancelling mass gatherings, closing school, issuing travel advisories, restricting movement, promoting and supporting alternative ways of working e.g. working from home [and] issuing proactive messaging around social distancing."

Ombler's paper said the Ministry of Health was "preparing primary care and DHBs for possible widespread community transmission".

Despite the paper insisting the focus was still on keeping it out, through border measures and case isolation, Government officials by March 10 were not entertaining the idea of imposing a requirement that all new entrants self-isolate for 14 days, a policy Israel had just unveiled.

By March 12, Cabinet was considering upgrading the United States and Europe to Category 1B countries, requiring travellers from these locations to self-isolate for 14 days. However, just two days later, Jacinda Ardern announced that the whole world (minus Australia and the Pacific Islands) would be Category 1B - adopting Israel's policy.

The March 14 Cabinet briefing shows the urgency under which the decision, which came alongside an announcement that the March 15 terror attack anniversary event would be called off, was made.

"If you do proceed, an air gap of at least an hour is needed to inform Governments and critical domestic partners," the briefing states.

"If our borders remain as open as they are now, there is a risk current people flows to New Zealand could precipitate more cases and fuel early stages of epidemic here. Other countries have seen a few initial cases rapidly escalate into very high peaks of cases in a matter of days. While our health system is prepared, there is more that could be done in a short period of time to increase our capacity to respond (eg increased testing capacity at large-scale). The more we postpone cases, the better the healthcare system can function, the lower the mortality rate, and the higher the share of the population that will be vaccinated before it gets infected."

The question of testing was one that became increasingly urgent over the weekend. By the end of the day on March 16, the country had completed just 522 tests for Covid-19. The criteria for testing were strict, requiring a narrow set of symptoms and the patient to have been overseas or exposed to another confirmed case.

Although Ardern had said the previous week that doctors could waive these criteria at their discretion, the message didn't seem to filter down until it was reiterated on the morning of March 17. That day, 620 tests were conducted - more in 24 hours than in the previous month and a half.

From that point on, New Zealand continued to expand its testing capacity with few hiccups, outside of instances in which negative test results sometimes took up to a week to report back.

However, the lack of testing would come back to bite New Zealand. By the end of the day on March 16, the country had conducted 522 tests and found eight cases. However, according to Ministry of Health data, an additional 87 people with Covid-19 had entered the country over the same period. The last of these was only identified on April 25.

Imperial College London paper changes everything

March 16 also saw the release of an academic paper that would go on to reshape government policy around the world, including the United States, United Kingdom and New Zealand.

The UK had been pursuing a policy of "herd immunity", hoping to protect older people and vulnerable people while the rest of the population would be exposed to the virus and build up immunity to it. This would allow the country to undergo a brief, sharp shock to public health and the economy but then move forward without having to worry about the virus, the theory went.

The Imperial College London modelled what such a policy would result in: 510,000 deaths in the United Kingdom. In the United States, such a strategy could kill 2.2 million, the ICL paper reported.

The authors then decided to analyse the difference in outcome between a number of different policy interventions, which they grouped into "mitigation" and "suppression". Mitigation "focuses on slowing but not necessarily stopping epidemic spread – reducing peak healthcare demand while protecting those most at risk of severe disease from infection," the paper's author, Neil Ferguson, wrote, while suppression "aims to reverse epidemic growth, reducing case numbers to low levels and maintaining that situation indefinitely".

Three mitigation options were considered, in various combinations: self-isolation of symptomatic cases; a voluntary quarantine of all households with symptomatic cases where half of households comply; and social distancing of those over 70.

Choosing to implement all three mitigation options would have a major impact, Ferguson wrote, but it still wouldn't be enough to avert mass death. Under optimal mitigation, 250,000 would die in the UK and 1.1 million in the US.

"This 'optimal' mitigation scenario would still result in an eight-fold higher peak demand on critical care beds over and above the available surge capacity in both [Great Britain] and the US," Ferguson stated.

Suppression, meanwhile, was effectively lockdown. It assumed self-isolation of symptomatic cases and household quarantine as outlined above, then piled on a degree of social distancing that would reduce all contact outside the home, school or workplace by 75 percent. In workplaces, contact rates would drop by a quarter as more people worked from home and offices put in place protective measures to minimise physical contact. Alongside this, all schools would shut, as would 75 percent of universities.

The moment suppression measures were lifted, cases would begin to rise again, according to the paper. It would be possible to manage this by reopening the country for a short period and then shutting it down again before the number of cases overwhelmed the health system's capacity. Ferguson estimated that countries would have to enter lockdown for two months, then reopen for one month, repeated ad infinitum until a vaccine or effective treatment is developed.

New Zealand quickly pivoted to a suppression strategy after the release of the ICL report, abandoning discussions of flattening the curve (a mitigation approach) in favour of what the Prime Minister called "managed peaks". This seemed to echo the chart below from the ICL paper, which showed how suppression would operate.

"Our approach - and this is what successful countries have been doing - is you want to have a series of small peaks over a longer period of time and you amplify up quite stringent controls to ensure that you don't exceed your health system capacity," Bloomfield said on March 19. "Then as it goes down again, you can ease those and be prepared to ramp them up again."

Bloomfield said at the time the paper "was very critical in our response over the last few days to inform our shift from a 'flattening the curve' to a series of smaller curves. What they were able to do was identify what measures you need to take to not just flatten the curve but to keep any outbreaks at a level that your health system can still cope with and that's the position we want New Zealand to be in".

The same idea is visible in the below chart from a March 18 All-of-Government (AOG) document entitled "mitigation vs suppression".

This document also emphasises New Zealand's turn to a stamp-it-out approach. "Our strategy is focused on keeping Covid-19 out, stamping it out and slowing it down," it states.

"Our aim is to prevent widespread outbreaks. Allowing widespread outbreaks [...] will significantly overwhelm the health system. The strategy centres on border restrictions, intense testing, aggressive contact tracing, and stringent self-isolation and quarantine."

The next day, the Government announced what seemed by then a foregone conclusion: the borders would close. The paper outlining this decision stated that new entrants could not be counted on to follow the restrictions that may be needed to fight Covid-19.

"If we continue to allow people to enter New Zealand who do not have a realistic prospect of self-isolation or who cannot return home easily, there will be a significant call on resources to either support them or enforce compliance," it stated. That day, Clark also announced a new policy on mass gatherings, limiting indoor events to 100 people and outdoor events to 500.

In the short period after the ICL paper debuted, Cabinet developed a world-first policy that formalised its recommendations: the alert level system.

Announced on March 21, the alert levels not only helped New Zealand understand what was expected of them as the outbreak worsened or alleviated, but also provided a formal measure by which the Government could introduce stricter measures in response to growth in case numbers.

While the ICL paper recommended using the number of cases in ICU as a benchmark for when to reintroduce restrictions, such a proposal would not work for a population of New Zealand's scale. Instead, the alert level system used the way in which cases were spreading - through community transmission, clusters or imported from overseas - as the benchmark for when a new alert level might be called for.

A March 20 paper outlining the alert level system made clear that it was needed: "If community transmission becomes widespread we will have lost the opportunity gained by closing the border. International advice is that for each case we may be missing nine. Even with no further imported cases, if we have missed early cases transmitting silently, we could suddenly face an exponential rise in cases as has happened elsewhere."

Indeed, there were at least 287 cases in the country by the end of that day, according to Ministry of Health data, but just 39 had been identified.

Although it understood the need for suppression, the paper still didn't recommend any serious measures, let alone entertain the idea of the four-week lockdown that was to be announced four days later.

"At present, the whole of New Zealand is at Level 1, but we have already applied parts of Level 2, namely maximum border restrictions and tightening of restrictions on mass gatherings," it stated.

"We recommend New Zealand move completely to Level 2 immediately and remain there for up to 30 days initially. The move to Level 2 reflects the heightened risk of importing Covid-19 cases at this time as many New Zealanders return home from overseas and we see an uptick in reported cases here."

The path to lockdown

When Ardern announced the alert level system on March 21, it was met with an immediate outcry by epidemiologists and other health professionals for a move to Level 4.

Baker, who had been calling for lockdown for the better part of a week, reiterated his view on RNZ shortly after the announcement. He was convinced New Zealand's testing wasn't ready to find the cases out there and also raised a handful of concerns about contact tracing.

In the end, it was the contact tracing that would prove the slowest to scale up. A report on contact tracing commissioned by the Ministry of Health from University of Otago infectious diseases expert Ayesha Verrall found Public Health Units (PHUs) were overwhelmed by the case numbers they faced in late March.

"When New Zealand moved to Alert Level 4 on 25 March, many PHUs were at or beyond their capacity to manage cases and contacts, even with increasing support from the newly established [National Close Contact Service]. During that week, nationwide daily case numbers ranged from 70-86," Verrall wrote.

Even two weeks into lockdown, only 60 percent of contacts could be easily reached by phone and PHUs had no insight into what happened to cases they referred to the centralised NCCS. Verrall wanted to see the PHUs and NCCS able to trace all the contacts of 1000 new cases every day, up from just 70 on March 25.

In fact, the documents released by the Government show that by March 18, PHUs could trace fewer than 50 cases a day. On the same day, 39 Covid-19 cases entered the country. The situation was quickly spiralling out of control.

Exactly why the country was so unprepared for Covid-19 remains unclear. Newsroom has previously reported on international assessments in which New Zealand scored just 54 out of 100 points for pandemic preparedness. Domestic epidemiologists, including Baker and fellow University of Otago expert Nick Wilson, had long raised these concerns.

Nonetheless, the country's poor preparedness meant there was no viable alternative to lockdown. While countries like Taiwan and South Korea have managed to chart a suppression or elimination path without resorting to lockdowns, they also have far more robust public health systems than New Zealand.

Ardern's announcement of the alert level system was somewhat overshadowed by the revelation that day that there were two new cases with unknown sources of infection. "We can’t rule out that there was community transmission, but what we’re interested to find out is whether that community transmission happened there or somewhere else in the country," Bloomfield said that morning.

On Monday, March 23, Bloomfield confirmed that one of the cases, alongside a new one from the previous day, were community transmission.

"Across all cases, there remain currently two that we cannot be certain where the infection came from and we are therefore treating them as community transmission," he said.

This revelation led to the announcement later that day of the move to Level 4.

A Cabinet briefing from March 23 notes, "Cases over the recent days suggest community transmission of Covid-19 is highly likely."

"If community transmission becomes widespread we will have lost the opportunity gained by closing the border. Once community transmission is established, the number of cases will double every five days. It is critical that New Zealand acts decisively to break the chain of community transmission to protect our communities (in particular priority populations) and prevent overwhelming the health system. Early containment will increase our chances of preventing exponential growth in case numbers.

"New Zealand is at a tipping point. We have a short window of opportunity to take a trajectory more similar to Singapore and others who have taken an early and strong approach to containment, and avoid the trajectory of Europe, where community transmission has taken hold. We should move to Level 3 at a national level as soon as practicable. Level 3 further reinforces the need for physical distancing and is a step short of declaring a local or national state of emergency.

"A move to Level 4 is inevitable in the near future, if we are to break community transmission. We recommend an initial period of four weeks to break the community transmission that is already very likely under way. We recommend that Level 4 is implemented as soon as possible."

The announcement came just 24 days after New Zealand confirmed its first case. At the time, we thought we had 102 cases, but there were at least 433 cases in the country by the end of the day.

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