With Auckland On A ‘Knife Edge’, Experts Urge Against Level 2

Covid-19

Epidemiologists, disease modellers and public health experts unanimously oppose a move to Level 2 for the supercity while undetected community transmission continues, Marc Daalder reports

Analysis: It is too early for Auckland to move to Level 2, with nine cases from the past two weeks yet to be linked, experts have told Newsroom.

A range of epidemiologists, disease modellers and other public health experts all urged Cabinet to be cautious when it meets on Monday to decide whether Auckland should step out of lockdown on Wednesday. Auckland, they said, should stay at Level 3.

They said the Delta outbreak may not be wildly uncontrolled, but it isn’t fully under control either. That follows Director-General of Health Ashley Bloomfield telling Newsroom in an exclusive interview on Wednesday morning that the ongoing proliferation of unlinked cases shows there are “still some chains of transmission out there – a few – that we haven’t identified through the community testing. We will be wanting to see those numbers of unlinked cases come down.”

Unlinked cases

Bloomfield’s comments came before the shock of 45 new cases in Auckland on a single day, 12 of which were unlinked. Many of those cases have since been connected to the main cluster, but there are still more mystery cases now than when the health boss spoke to Newsroom.

Unlinked cases remained the main cause for concern among the experts spoken to by Newsroom as well.

“Those unlinked cases, some of them have been quite ominous,” University of Otago epidemiologist Michael Baker said.

“People turn up, quite out of the blue, at the hospital as a positive or are picked up in custodial settings like police and corrections, through routine testing, that normally suggests there’s quite a bit of undetected transmission in the community. We’re absolutely still on that knife edge.”

Fellow Otago epidemiologist Nick Wilson agreed, saying the numerous instances of people turning up at hospital for other matters and testing positive by coincidence flagged the possibility of more widespread undetected transmission. It was just statistically unlikely that so many cases would be cropping up in that setting otherwise.

Sue Crengle, a public health expert and Māori health researcher at Otago University and co-leader of Te Rōpū Whakakaupapa Urutā, said she wasn’t convinced the outbreak is contained.

“We have questions around the extent of unidentified Covid cases in the community amongst young people who are not going to end up presenting to hospital,” she said. “There are a number of questions about, is this a slow tail or is this the beginning of an increase in the number of cases arising from the reduction in the alert levels or is this signifying that there’s actually more circulating out there?”

And University of Otago public health expert Amanda Kvalsvig told Newsroom that Auckland should stick out Level 3 to stamp out the virus.

“A key principle of managing this highly infectious virus is that it’s really only controllable while numbers are small, so early on is the time to throw everything you have at it. That’s the crossroads we are at now,” she said.

“A really big effort now to stamp out transmission can pay for itself over and over in terms of protecting people, the health system, children’s education, and all of the other benefits of a functioning society. It will look like an overreaction. It always does, because you’re responding to prevent the future growth of an outbreak, not the numbers you can see today.”

Level 2 could overwhelm the health system

Disease modellers from Te Pūnaha Matatini also said it was too early for Auckland to move to Level 2.

“We’ve still got the mystery cases popping up. We had cases in Middlemore [on Thursday]. When you have cases like that popping up when you’re not looking, when you’re not expecting them, that’s signifying that the outbreak isn’t super contained,” University of Canterbury mathematics professor Michael Plank said.

Plank’s colleague at Te Pūnaha Matatini and Manaaki Whenua – Landcare Research mathematical modeller Rachelle Binny agreed.

“Easing Auckland to Level 2 on Monday would be a risky move,” she said.

The danger of moving too early is significant, the modellers said.

“The current levels of vaccination are likely still too low to prevent case numbers taking off again if Auckland moves down to Level 2,” Binny told Newsroom.

Less than 40 percent of Aucklanders were fully vaccinated as of Tuesday. For Māori, that rate falls to less than a quarter.

“Moving to Level 2 risks adding fuel to the fire and it would be quite likely see a rapid increase in case numbers. That would inevitably lead to hospitalisations and deaths,” Plank agreed. “It’s quite a big jump from Level 3 to 2, if you think of the types of things that are allowed, the movement, the contact and mixing that happens at Level 2 compared to 3.”

Is there a non-health justification to move down to Level 2, such as concern about increasing non-compliance? Despite frequent anecdotes, available movement data shows that Aucklanders are by and large following the rules. Movement in the supercity is consistent with previous Level 3 lockdowns, like the August 2020 one.

If elimination fails

Crengle acknowledges that staying in Level 3 for longer will frustrate Aucklanders who are exhausted after seven weeks of lockdown. Some are beginning to ask whether Delta can ever be eliminated, now that case numbers have flatlined between about 10 and 25, on average, for several weeks.

Political commentators who have questioned the viability of elimination appear to assume the next step is a rapid move down the alert levels. Plank says that’s a misconception.

“It is looking like it is going to be very difficult to eliminate this outbreak. Not impossible, but certainly very difficult. However, the alternative option is not just to wave the white flag, get back to normal and let it rip,” he said.

“Really the only alternative is to suppress it. And, to be honest, that doesn’t really look that different in terms of the public health response from the elimination strategy. At least in the short term.

“When we get higher vaccination rates, that will increase our options in terms of relaxing restrictions and tolerating slightly higher levels of community transmission. At the moment, allowing case numbers to grow very rapidly would likely put significant strain on our health system in a very short period of time.”

Baker agreed, saying that a suppression approach could see Auckland in some form of lockdown for longer than successfully eliminating the virus.

“I think there is still the possibility of stamping it out and I think that should be a big priority. Even if we can’t, I think Alert Level 3 is what you need, basically. People staying home for much of the time,” he said.

“All this is doing is buying us time to get the vaccination rates we need. You’d have to keep that barrier around Auckland, you’d keep the pressure on the virus, and you’d go absolutely all out on increasing vaccination coverage.

“Then, at a certain point, you’d be able to scale down those controls at some stage over the next few months. But not yet.”