Most Covid-19 cases in New Zealand should develop symptoms by next Tuesday after potential "super-spreader" events over the last fortnight, a Kiwi Covid-19 modeller says.
Professor Michael Plank from the University of Canterbury told Seven Sharp on Friday evening the Government's decision to extend the nationwide Level 4 lockdown until at least next Tuesday was in part to help manage cases that aren't yet known.
"By Tuesday we will have had a full week since the lockdown started, so by then we would expect the majority of people who were infected before the lockdown will have gone through the whole incubation period and would start to develop symptoms," Plank said.
"So provided everyone continues to come forward for testing if they have symptoms, we should start to have a clearer picture of the size of the outbreak by then.
"But it is likely to take a bit longer, particularly in Auckland, for the effect of the lockdown to kick in and the numbers to come down."
The lockdown for NZ excluding Auckland and the Coromandel was extended by Prime Minister Jacinda Ardern on Friday afternoon after 11 new community cases were reported, three of which were located in Wellington.
The new cases took New Zealand's total number of community cases in the outbreak to 31, telling modellers like Plank more cases will come in over the next few days.
"In a sense, that's good news because it means our contact tracers are doing their job and tracking down those contacts and finding the cases we suspect are out there," Plank said.
"I think it's likely we could end up with the total number of cases ending up between 50 and 100 over the next few days."
Plank did concede it was "significant" that the outbreak had now stretched from Auckland and the Coromandel to Wellington though.
"I'll probably cop a bit of flack for saying this but it shows there's nothing really special about Wellington and this shows that there could be cases anywhere in the country, because there would have been a lot of people travelling to and from Auckland over that period of time.
"So we need to remain on our guard and I think it was the right decision to extend the lockdown for the whole of New Zealand."
Plank added there is a high chance the outbreak could have had some "super-spreader" events with locations of interest listed including bars, churches, education facilities and shopping malls.
"As we get the test results in from people that went to those locations over the next few days we could see some significant case numbers from those.
"The good news is the lockdown will have stopped those locations of interest from happening going forward.
"We should see that list of locations start to stabilise over the next few days."