Two more returnees who stayed at the same New Zealand hotel at the same time as Sunday’s coronavirus case have tested positive after finishing their quarantine.
The two people are asymptomatic and had already completed their managed isolation at Auckland’s Pullman hotel and returned two negative tests, the Department of Health said.
It is yet to be confirmed if they are recent or historic infections and further testing is urgently being carried out.
The cases are now in isolation at home while investigators track how they contracted the disease – and their activities since their release.
Australia’s acting chief medical officer, Prof Michael Kidd, said the two cases had the South African variant of Covid and the situation was “evolving rapidly”.
The fresh cases could see a further delay to Australia reopening its travel bubble with New Zealand. Travel was suspended on Monday for 72 hours after New Zealand’s first case in two months emerged on Sunday.
Kidd said Australia was expecting further advice overnight from New Zealand and a decision would be made on Thursday. The travel suspension had been due to end at 2pm on Thursday.
Epidemiologist Michael Baker told the New Zealand Herald the two new cases could be weak positives that were old cases.
Some people who had coronavirus, even months ago, and recovered could “still have fragments of the RNA from the virus left in their respiratory systems and this is being picked up”, Baker said.
The fresh cases emerged after encouraging signs that Sunday’s case in Northland – a 56-year-old woman – had not led to significant spread of the virus. All 16 close contacts of the infected woman returned negative tests, health officials said on Wednesday.
About 10,000 New Zealanders took Covid-19 tests on Tuesday, of which 8,000 were in Auckland and Northland, making it one of the highest testing rates in the world.
“We are still investigating but this is an encouraging response and does provide us some reassurance,” the Covid response minister, Chris Hipkins, said at the time.
The infected woman, a 56-year-old New Zealander, remains in self-isolation, as do all her close contacts.
Despite contracting the highly infectious South African variant of the disease, the woman had few respiratory symptoms and was diligent about hygiene and recording her movements. Health authorities believe this may be why her illness has failed to spread significantly after she left mandatory quarantine at the Pullman hotel In Auckland where she isolated on her arrival from Europe.
Shaun Hendy, who works on the government’s Covid-19 team modelling the disease, said the fact the case had not spread was not uncommon. “This is not that unusual for Covid-19 as it is frequently passed on by super-spreaders or at super-spreading events,” said Hendy. “That is, lots of people don’t pass it on, but a few pass it on to lots. This is probably still the case even for the new variants, however, we are still learning [about them].”
All of the staff working at the Pullman have also tested negative. How the woman contracted the disease is still under investigation, but an infected surface at the Pullman is thought to be the most likely culprit.
“There are encouraging signs in Northland but we are not breathing a sigh of relief just yet,” said Dr Ashley Bloomfield, New Zealand’s director general of health.
The case has caused ripples of unease around the country.
In Nelson, a cafe banned anyone who was recently released from managed isolation. The owner said the risk to his clientele was too great. “Anyone that manages a business assesses risks, some quantifiable, some not ... this seemed to be a no-brainer,” Allen Chambers told Stuff.
“We run a social business with customers who can be vulnerable – elderly, infirm, pregnant,” Chambers said. “I’m surprised that there’s not more of a reaction amongst business owners.”
Hipkins said since the case was confirmed there had been a sharp rise in New Zealanders using the Covid tracer app, after a decline over the summer months.