The latest spike in cases could be a sign elimination is not working and Delta is spreading in vulnerable communities, experts say.
There were 45 new community cases of COVID-19 announced on Wednesday, all in Auckland.
Of the new cases, 33 are known to be household or contacts of existing cases, Director-General of Health Dr Ashley Bloomfield said. All have been isolating at home or in quarantine during their infectious period.
There are 12 cases that are unlinked; for six of those, there are potential links visible.
Dr Bloomfield said a proportion of the cases were among groups of people who were in transitional or emergency housing.
"Teams are working very hard with a range of agencies to support those people," he said.
University of Canterbury associate professor Alex James said the increase could be the first sign of a rise in transmission due to the drop to alert level 3.
"Even under level 4, case numbers were dropping very slowly, if at all. If alert level 3 can't contain this outbreak we may need to face the truth that elimination hasn't worked."
Prof James said the spike had been accompanied by a slowdown in vaccination rates.
National Hauora Coalition clinical director Dr Rawiri McKree Jansen (Ngāti Raukawa, Ngāti Hinerangi) said Delta was now circulating in communities that were vulnerable due to poverty and overcrowded housing.
Historically they had been poorly served by both the health and social sectors.
He said it would be necessary to devote extra resources, effort and personnel adept at working with different cultures to try and bring the outbreaks under control.
University of Otago senior lecturer Lesley Gray, who has worked in disaster risk reduction, said it was no surprise that Delta was spreading through overcrowded communities.
"This is not the fault of such populations; it is the circumstances and limited resources that limit options. Such circumstances are at the heart of the concept of disaster vulnerability.
"Our aim as a country should be to leave 'no one behind' when rebuilding from this pandemic."
University of Canterbury Professor Michael Plank (Te Pūnaha Matatini) said the Government faced some tough decisions if today's numbers were the start of a trend.
"Reducing the alert level is likely to cause an explosion in cases and, with a large number of people either unvaccinated or yet to receive their second dose, the population is still vulnerable.
"Level 3 may be enough to keep the outbreak in check, but that could mean Auckland is stuck in level 3 for a long time until a lot more people have been able to get their second dose.
"The Delta variant is really good at finding unvaccinated people. So the message is clear: get vaccinated."
However, Prof James said Auckland children had missed nearly an entire school term already so there needed to be a debate on how much more their education should be affected.
"We've seen from other countries the poor mental health outcomes and rising inequality that online school and closed nurseries bring.
"We need to start a conversation about how long we want this to go on for and how to find a middle ground between a long, detrimental lockdown and the possibility of upward spiralling case numbers in level 2."
RNZ
