There is no evidence the person who tested positive for Covid-19 in South Korea after travelling from New Zealand was infected here, Health Minister Chris Hipkins says.
But amid an "abundance of caution", officials were contact-tracing two rows in front of and behind the person, who left New Zealand from Christchurch Airport on July 21.
Hipkins has given the daily Covid-19 update with director general of health Ashley Bloomfield.
The person had been in New Zealand since March 18 on a visitor's visa.
Five contacts of the household where the person had been living in Auckland were all well but are in self-isolation and will be tested today.
The person had stayed a night in Christchurch before catching a Singapore Airlines flight home to South Korea.
They spent 14 hours and 20 minutes in a transit lounge at Changi Airport, along with people who had travelled from other parts of the world. It is believed they were infected there.
The health ministry hasn't spoken with the person because they're not a New Zealand citizen and so needed to seek permission to do so.
Because they haven't spoken with the individual, all possible close contacts can't yet be identified, said Bloomfield. But 170 had been identified and "the vast majority" had been spoken to.
Bloomfield said there was nothing in community testing in Auckland to indicate there was any community infection.
The person is also having their movements traced as a precaution but the risk is considered to be low.
They were tested on arrival in South Korea but there was a delay for their result. By yesterday they still hadn't had a second test but health officials were operating on the basis they'd had a second test and it was positive as a precaution.
Hipkins said there was a variety of scenarios and officials were still working out which one was correct - but were working on a worst-case basis.
One new case
Bloomfield today revealed one new Covid case - a woman in her 20s who travelled from Afghanistan via Dubai, arriving in New Zealand on July 14.
She had been staying at the Distinction Hotel in Hamilton and tested negative on day three but returned a weak positive on day 12 and has moved to an Auckland quarantine facility.
"This case again reinforces why we test people twice during their time in managed isolation," Bloomfield said.
"The Covid-19 infection may take longer to develop in some people and a second test is an important check used to find out if a person is safe to leave managed isolation."
It has been 88 days since the last case of Covid-19 was acquired locally from an unknown source.
One previously reported case is now considered to have recovered, which means the total number of active cases in New Zealand remains at 21.
There is no one in New Zealand receiving hospital-level care for Covid-19.
Our total number of confirmed cases is now 1207, which is the number we report to the World Health Organization.
More than 1100 tests were processed yesterday, including 872 in the community.
That brings the total number of tests completed to date 457,334.
Hipkins said the current testing rates still were not where the Government expected them to be.
He said the health ministry was working "very, very hard" to work out why numbers were low.
He called it "frustrating" that the numbers weren't high enough.
"I don't think, in any of this there is a deliberate attempt to suppress testing numbers."
Bloomfield said the influenza rates were about a third of what they were normally which was impacting test results.
Bloomfield said it was good to see the number of people being tested in the community had increased over the last week.
Bloomfield said the introduction of a throat-swab test had increased uptake.
Bloomfield once again urged New Zealanders to download and use the Covid Tracer app.
Hipkins said there were robust systems in place for staff working across managed isolation facilities to keep them safe.
Hipkins said he'd ordered an independent review rostering and risks which was underway at the moment.
From Saturday DHBs will take over the delivery of health services in border facilities, which are currently being provided by contractors.
Anyone working in a facility will have to adhere to a stand-down period and return a negative test before working elsewhere.
The Health Ministry is working in advice around masks if regions were to move up alert levels again.
• Covid 19 coronavirus: Victoria coronavirus cases soar to horror levels
• Covid-19 coronavirus: Pullman Hotel escapee pleads guilty
• Barry Soper: Jacinda Ardern's strategy to focus on conquering Covid, not election
• Covid 19 coronavirus: Two new cases of Covid today; Health Minister Chris Hipkins unhappy with testing numbers
The ministry also said yesterday it was working on rostering guidelines to limit nurses working across multiple sites, as revealed by the Herald last week.
The ministry said it was working through updated advice with the Covid-19 Clinical Governance Group which has oversight of clinical practices, including nursing, within managed isolation and quarantine facilities.
"There are already in place systems and processes at the managed isolation facilities which are robust and sufficient to keep safe the nurses working there, and the individuals they interact with.
"Nurses are also already provided with guidance on infection control, PPE and procedures to reduce the risk of transmission."
The updated advice will recommend rostering guidelines, limiting staff same-day redeployment to different workplaces and improving managers' knowledge of which staff have secondary employment so additional risk factors can be assessed and managed.
"Nurses are trained professionals, well versed in infection prevention and control and in the Covid-19 context.
"Within managed isolation and quarantine facilities nurses have access to appropriate PPE, follow sound personal hygiene practices and keep to physical distancing requirements. They also have regular health checks and are regularly offered testing for Covid-19, even if they are not symptomatic."
The updated advice will apply to all healthcare staff working in managed isolation and quarantine facilities. It will be shared tomorrow with DHBs that have managed isolation and quarantine facilities in their region, before being finalised.