Block the border holes or get ready for another bad report

Dr Eric Crampton
Newsroom
22 December, 2020

Last week, the government finally released the Simpson-Roche report detailing the failures that led to August’s Covid outbreak in Auckland. Some of the failures, like inadequate testing regimes for MIQ staff and border workers, were entirely preventable. It would have been difficult to look at the testing regimes, as they were in July, and feel confident in the system.

If New Zealand’s next outbreak comes over our summer holidays, what will the next Simpson-Roche report be likely to say about it when it is eventually released? What foreseeable failures are likely to lead to the next outbreak, and what could we do now to prevent it?

Last week’s issue of The New Zealand Medical Journal last week provided a potential foreshadowing of a report we should hope need never be written.

The University of Otago’s epidemiologists listed a series of measures that would obviously help to reduce the risk of future outbreaks. Many are simple; some would take more work. But when outbreaks cost billions of dollars, in addition to obvious health costs and distress, even a percentage point reduction in the risk of an outbreak can be worth millions.

The epidemiologists’ suggested measures work to reduce the risk of transmission, to reduce the risk of missed cases, and to reduce the costs of any missed case that does make it through.

They suggest adjusting the intensity of border control measures to the risk involved in travel from different places. It makes little sense, for example, that travellers from places where Covid is widespread and transmission is uncontrolled are treated the same way as travellers from places without Covid, like the Covid-free islands, Taiwan, and parts of Australia.

A traffic-light system, designating more stringent controls for travellers from risky places, could help.

On the simple and obvious range of the spectrum, the epidemiologists recommend reviewing testing regimes for incoming travellers.

Currently, travellers are subject to two PCR tests while in MIQ. The tests are costly and invasive, and accurate. Rapid antigen-based saliva tests have been available for months but are not as accurate as PCR tests. Good testing protocols can consider trade-offs between frequent tests that are cheaper and less accurate, and less frequent tests that are more accurate.

But, since August, accurate PCR saliva-based testing following the University of Illinois’ SHIELD system protocols have been possible. The tests provide faster results, are accurate, provide less risk of transmission during testing, and are much less expensive to process. Where a regular nasal swab test can induce sneezing, the Illinois test only requires saliva collection.

Shifting from one test per week to near-daily testing would have obvious advantages.

Faster identification of positive cases would mean that those who were infected would be more quickly shuttled to dedicated facilities where they would be less likely to pass the virus to others.

And extending near-daily testing to border staff would make it far more likely any infections would be caught more quickly, reducing transmission risk.

Other obvious and relatively inexpensive measures recommended by the Otago epidemiologists included enhanced monitoring of close contacts of border workers, wastewater testing at border facilities and in areas near border facilities, and pre-departure testing for travellers coming from risky places.

In the heat of an election campaign, National’s proposals for mandatory testing before travelling were portrayed as impracticable, ineffective, or both. But saliva-based antigen tests, like the Abbott BinaxNOW test which recently received FDA Emergency Use Authorisation, could be used right at the airport departure gate. Testing at the gate would reduce the risk that infectious people board the plane and infect their fellow passengers. It certainly would not substitute for a stay in MIQ, but it would reduce the number of arriving cases.

Reducing the number of arriving Covid cases, or at least preventing that number from increasing, matters. New Zealand’s health system can only handle so many positive cases, and that constraint seems to guide much of how MIQ operates.

There are many opportunities for the MIQ system to expand to handle more arrivals, safely. People arriving from low-risk places could stay in facilities that had been ruled out because they were too far from hospitals, for example, leaving more room in other facilities for travellers from riskier places.

The MIQ system has been exceptionally reluctant to consider those kinds of options. It makes little sense, unless measures that would allow more people into MIQ from risky places would mean more positive cases than officials believe the health system can safely handle.

Preventing those who are infected from boarding the plane reduces the number of positive cases arriving here, which means that more travellers overall could be accommodated. More Kiwis could safely return home, and more people could safely join us, if those with Covid were less likely to board flights here in the first place.

And that brings us to the Otago epidemiologists’ more difficult option – but one that is well worth considering. They suggest running MIQ facilities in high-risk jurisdictions; they had made similar suggestion in October. The government could set a pilot programme providing MIQ facilities in a country that is the source of many positive cases found in our MIQ system. Travellers could isolate before travel to New Zealand, reducing the risk of transmission.

MIQ in New Zealand would still be required if there were risk that passengers could contract the virus at the airport. But it would reduce the number of positive cases arriving here, enabling more Kiwis to come home safely. And an MIQ facility in the UK would also reduce the risk presented by the more contagious form of Covid now prevalent there.

It would be impossible to bolt every possible door against future outbreaks. But Otago’s epidemiologists point out several opportunities for making our borders safer. Far better to bolt those particular doors now, rather than read about them again in a future Simpson-Roche report.

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