Coronavirus: Another day of zero community cases should assure Kiwis after outbreak concerns - Michael Baker

An epidemiologist says Kiwis can feel reassured that despite concern last week New Zealand faced another outbreak, no new community cases have been found. 

Three community cases were recorded last week in connection to a port worker who tested positive after working on a ship. Several Auckland locations - including a gym and a pub - visited by a case had to close for cleaning, while others who had also been at those places were asked to isolate and be tested. 

But so far no new community cases have popped up, with Tuesday marking another day where a positive result was only reported in a managed isolation facility. 

Epidemiologist Prof Michael Baker of the University of Otago says while more time is needed until New Zealand regains its elimination status, Kiwis can feel confident things are under control.

"We really need to wait four weeks from [the last case of community transmission], that last case being put into isolation before we can say we have returned to our elimination status," he told Newshub.

"But the fact that this chain of transmission is very well-defined, we have had over 20,000 tests in Auckland which have not returned a positive result, I think that is very reassuring for everyone at the moment."

With Kiwis alert to the new-found cases, Friday saw 7700 tests processed - the most in more than a month.

Prof Baker also believes it's "extremely unlikely" a child who returned a "possible positive COVID-19 test" after arriving in Japan had an active infection while they were recently in Napier. 

The Ministry of Health said on Tuesday that the child, who tested negative for COVID-19 before leaving New Zealand, was likely a historical case or had a false positive result, something under investigation by the Japanese. All other family members have tested negative for the illness. 

Prof Baker said it looked to be a historic case that's only just now been picked up due to routine testing on arrival in Japan. 

"The virus leaves a residue in the respiratory tract and that is there long after the person is actually infectious and then that is picked up through testing weeks or months later where the testing is done for other reasons."

He acknowledged that these surprise positives do create worry within communities, but felt assured by the cautious approach authorities are taking. The Hawke's Bay District Health Board alerted a Napier childcare centre the kid had been attending to the result. But it says there is a very low risk to others. 

"We are getting more used to these now and it is really a matter of looking at the circumstances of the case. Do they currently have symptoms, what is their history of contact with other people, where do they come from? That helps put this in context," Prof Baker said.