Modelling shows dire number of daily Covid cases by next month

Canterbury District Health Board senior responsible officer for the Covid-19 response, Dr Helen...
Canterbury District Health Board senior responsible officer for the Covid-19 response, Dr Helen Skinner, says the region's health system is well placed to manage any cases of Covid-19. Photo: Supplied
If the rate of spread in New Zealand’s current Covid-19 outbreak continues, there will be about 160 cases a day by early next month.

Based on this modelling by Canterbury University maths Professor Michael Plank yesterday, there would be more than 110 hospitalisations a week.

There were 71 new Covid-19 cases in the community on Thursday, which Director of Public Health Caroline McElnay said is "sobering but not unexpected".

On Wednesday, there were 53 new cases in Auckland and two in Waikato. On Tuesday 43 cases were reported in Auckland and three in Waikato and on Monday, 35 new cases emerged in Auckland, none in Waikato. There are 32 people with Covid in hospital and six in ICU.

Plank's modelling comes as a petition by Christchurch mayoral candidate Phil Mauger, calling for a border around the South Island, reached more than 2610 signatures this afternoon.

Michael Plank. Photo: UC
Michael Plank. Photo: UC
However, experts have said such a border would be impossible to seal off and would only buy weeks before Covid-19 arrives.

Plank said the current outbreak was seeing cases roughly doubling about every 12 days. If that trend continued, there would be about 160 cases a day by early November.

He said about 10 per cent of cases were requiring hospital care in the current outbreak.

With 160 new cases per day, 16 a day going to hospital would put “immense stress” on the country’s healthcare system.

“I think we are on a knife-edge in the sense that cases are clearly growing and the outbreak is clearly getting bigger,” Plank said.

New Zealand's current outbreak was growing "slightly slower" than the one in Victoria, Australia, was in mid August. Just a slight increase in transmission would put New Zealand on a similar trend.

"Eight weeks later, Victoria has over 600 Covid patients in hospital and around 130 in ICU. If this happened here it would take a terrible toll on our healthcare system," Plank said.

Victoria has a population of about 6.5 million and has seen more than 100 deaths in the current outbreak.

Plank said that “hopefully” getting more people vaccinated would slow that rate down.

However, a fellow modelling expert said it was too late for New Zealand to vaccinate its way out of the growth phase of the epidemic, and there was a strong case for return to level 4 lockdown in Auckland.

Dr Dion O’Neale at the University of Auckland said the current outbreak was not a random spike.

“In such a situation it is very tough to vaccinate our way out of the growing case numbers,” O’Neale said.

It took a couple of weeks for fully vaccinated people to develop a full immune response, during which time several generations of Covid-19 infections could get under way.

Currently about 56 per cent of the eligible population is fully vaccinated.

“There’s a strong case to be made for a temporary return to alert level 4 in Auckland as a circuit-breaker to limit transmission for a few weeks while we try to get as many people vaccinated as possible,” O’Neale said.

Canterbury District Health Board senior responsible officer for the Covid-19 response, Dr Helen Skinner, said the region's health system was well placed to manage any cases of Covid-19.

However, Skinner would not be drawn on the CDHB’s predictions for how many Covid-19 patients it could be treating in the coming weeks and months.

In terms of capacity at Christchurch Hospital, in addition to 32 dedicated beds in the newly established Parkside ground medical ward, there were 36 beds within ICU and children’s high care which could be used in a pandemic response.

The CDHB also had 32 negative pressure rooms across its facilities.








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