Public health experts want to see the Government mandate the wearing of masks on public transport and the scanning of QR codes if participation rates continue to fall, Marc Daalder reports

In the wake of numerous breaches of the managed isolation and quarantine (MIQ) system, public health experts have told Newsroom that a review of protocols within the facilities is needed alongside tougher restrictions on the general public.

The announcement on Friday evening of a new case of Covid-19 in the community in the form of a worker at the Jet Park Hotel quarantine facility has underscored the need to put an end to complacency, Siouxsie Wiles and Michael Baker say.

Wiles is a microbiologist and expert on infectious diseases at the University of Auckland and Baker is a professor of public health at the University of Otago, Wellington, a member of the Government’s Technical Advisory Group for Covid-19 and one of the architects of the elimination strategy.

Friday’s breach is the sixth community incursion spanning from MIQ in the last three months. That includes the Rydges Hotel worker who was infected via a lift, the small Auckland cluster that spread via a bin lid in MIQ, a healthcare worker infected at the Jet Park Hotel in September and two workers who were separately infected in the Sudima Christchurch facility hosting overseas mariners in November. It doesn’t include the Auckland August outbreak, the origins of which remain unknown, or the three port workers infected in October.

Swiss cheese management

That so many of these cases have occurred in such close succession could be a result of an overall increase in the number of Covid-19 cases in MIQ. This, in turn, is likely a result of increased saturation of the virus overseas, Wiles said.

The total number of cases of Covid-19 in the world has nearly doubled since the start of September.

“It’s escalating so fast so we should just be expecting more and more people who come to test positive, basically. That’s a real thing, we’re getting more people in who are positive and that’s more risk,” she said.

This increased risk has helped highlight potential weaknesses in the infection control protocols within MIQ facilities, Wiles said. She believes in the Swiss cheese model of risk management – it doesn’t matter if any one layer has holes in it, so long as enough layers are stacked together that nothing can penetrate all of them.

“These are multiple barriers or multi-layered defences,” Baker said.

But the numerous incursions in recent weeks indicate that some holes could be closed up or at least made smaller.

“Because our risk is increased, there were maybe holes that we didn’t realise that we didn’t see before because there weren’t so many positive cases,” she said.

Wiles points to the PPE worn in MIQ as a possible example of this – healthcare workers interacting face-to-face with returnees generally only wear surgical masks.

These masks are best at stopping droplets, which is one of the most effective ways that Covid-19 spreads, but they don’t really stop aerosol spread – transmission by air. For that, you need medical-grade masks which can filter out tiny virus particles.

“The feeling really is now that aerosol transmission is important. If that’s the case, is the right PPE being worn? Or are there other ways to do, for example, the Day 3 and Day 12 testing that would reduce the risk of transmission?” Wiles said.

These N95 masks come with their own challenges – they need to be a tight fit on the worker in question and require special training to use. At the same time, they’ll do a better job of stopping transmission even if they aren’t foolproof. It isn’t about eliminating all of the holes, just enough of them.

Director-General of Health Ashley Bloomfield said officials would be taking another look at infection control protocols in MIQ facilities, with particular regard for the N95 issue. However, he said that surgical masks would continue to be used in the interim.

Mandatory masks and scanning

Of course, MIQ isn’t the only layer of cheese. There are plenty before people arrive in the country as well. Baker would like to see pre-flight testing and different – more careful – treatment for people who are coming from high-risk areas like the United States and Europe.

“You could say that the risk of these events happening starts as soon as infected people get on the plane and come to New Zealand,” he said.

The flip side of this is the community, where public health recommendations around wearing masks on public transport and scanning QR codes at businesses are largely not being followed.

“In terms of our border security, it’s obviously multiple layers through that whole sequence. It even extends to testing workers but also testing people in the community with symptoms as another way of detecting outbreaks early and to wearing masks,” Baker said.

The Covid-19 case announced on Sunday, who was infected as part of the Friday MIQ breach, took a flight to Wellington from Auckland while infectious but didn’t wear a mask.

“If we’re serious about this, then we follow the model of Taiwan which has reengineered their society in sensible ways to make it far less conducive to transmission of a virus. They absolutely demonstrate that multi-barrier approach and of course, famously, they’ve now gone 200 days without local transmission and they’ve never needed a lockdown,” Baker said.

In Taiwan, mask use is mandatory on public transport. This law was passed after a month of no cases, not in response to rising case numbers.

Meanwhile in New Zealand, anecdotally, mask use on flights, buses and trains has declined significantly since the legal requirement to wear them was lifted when the country left Level 2. Very small proportions of people on public transport are now wearing masks.

Similarly, daily scan numbers have declined significantly from a peak of 2.5 million in mid-September to well below 1 million today. Outside of Labour Day, which was subject to intense publicity around scanning by the Government, there hasn’t been a day with more than 1 million scans in more than a month.

“I would like to see people doing that. If mandating it’s the only way that people will do it, then I think we have to start thinking about that,” Wiles said.

“I just don’t know how we get this message across, that this is our protection. This is how we make sure that something doesn’t become a big cluster. It needs to become a habit – these are habits we need to have in place for the next year or so.”

Marc Daalder is a senior political reporter based in Wellington who covers climate change, health, energy and violent extremism. Twitter/Bluesky: @marcdaalder

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