How Did New Zealand Control COVID-19?

August 9, 2020

The island country of 5 million declared the pandemic over in approximately 100 days. A team of clinicians explain the decision-making and rationale which drove their successes.

New Zealand, a modern small island nation, has become an emblematic champion of proper prevention and response to the coronavirus 2019 (COVID-19) pandemic.

Leading into this weekend, the country of approximately 5 million has just 2 dozen active COVID-19 cases—a full month after having reported absolutely none, on the backbone of strict initial travel policies, science-based government action, and strategies responsive to testing limitations.

What else went into New Zealand’s pandemic response—and what could serve as guidance for other countries?

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A new correspondence published in The New England Journal of Medicine from a team of New Zealand-based investigators at the University of Otago highlighted the public health successes of the country—measures which have brought New Zealand to the post-elimination phase of response approximately 100 days after its first case.

The trio of authors—Michael G. Baker, MB, ChB; Nick Wilson, MB, ChB, MPH; Andrew Anglemyer, PhD, MPH—wrote SARS-CoV-2 introduction to New Zealand was known to be imminent early on, due to a great rate of visiting tourists and students from Europe and China annually.

In fact, their disease models showed estimated wide pandemic spread, with capability to “overwhelm” the healthcare system and disproportionately affect Maori and Pacific persons.

“New Zealand began implementing its pandemic influenza plan in earnest in February, which included preparing hospitals for an influx of patients,” they wrote. “We also began instituting border-control policies to delay the pandemic’s arrival.”

The first New Zealand COVID-19 case was diagnosed February 26, around the same time that global agencies began reporting the SARS-CoV-2 infection was behaving more like a severe acute respiratory syndrome (SARS) than an influenza—giving investigators hope for containment.

Because of lacking testing and contact-tracing capability in mid-March, the country’s leaders made a dramatic and critical switch in strategy: from mitigating the disease, to eliminating it.

A countrywide lockdown—Alert Level 4—was implemented on March 26.

“After 5 weeks, and with the number of new cases declining rapidly, New Zealand moved to Alert Level 3 for an additional 2 weeks, resulting in a total of 7 weeks of what was essentially a national stay-at-home order,” authors wrote.

It was in early May that the last identified COVID-19 case was observed in the community; with the patient placed in isolated, the country had ended its community spread. On June 8, the New Zealand moved to Alert Level 1—in 103 days, they had declared the pandemic over in the country.

At the time of the paper’s publishing, New Zealand had just 1569 cases, 22 deaths, and a coronavirus-related mortality of 4 per 1 million—the lowest reported rate among 37 nations in the Organization for Economic Cooperation and Development.

“Many parts of the domestic economy are now operating at pre-COVID levels,” authors wrote. “Planning is under way for cautious relaxing of some border-control policies that may permit quarantine-free travel from jurisdictions that have eliminated COVID-19 or that never had cases.”

However, the post-elimination stage of the pandemic is not certain for safety. The authors noted the only cases identified in the country are via international travelers kept in government-managed quarantine or isolation for 2 weeks post-arrival. Failures of border control or continued quarantine/isolation policies could result in new spread.

“New Zealand needs to plan to respond to resurgences with a range of control measures, including mass masking, which hasn’t been part of our response to date,” authors wrote.

But there are takeaways from the early and immediate successes of the New Zealand response. The authors credited the combination of immediate risk assessment driven by science, with the decisive actions of the government.

Additionally, the country’s border-control strategies, as well as both community-based and individual case-based control measures, were overall effective in eliminating the virus’ presence when mitigation was no longer feasible.

Lastly, the authors praised their leader’s message.

“Prime Minister Jacinda Ardern provided empathic leadership and effectively communicated key messages to the public—framing combating the pandemic as the work of a unified “team of 5 million”—which resulted in high public confidence and adherence to a suite of relatively burdensome pandemic-control measures,” they wrote.