A cluster is considered to be closed when there have been no new cases for two incubation periods (ie, 28 days) from the date when all cases have completed isolation.
In its update today, the Ministry of Health welcomed the latest guidance on the use of masks from the World Health Organisation.
That guidance was consistent with the ministry's current advice that "mass-masking" is not required.
"The WHO emphasises that masks should be part of a comprehensive strategy and that much of their updated guidance relates to countries with a high degree of community transmission," the ministry said in a statement.
"Fortunately, in New Zealand we are increasingly confident we have no community transmission which supports our ongoing move down through our alert levels."
The NZ Covid Tracer app has now recorded 511,645 registrations – an increase of 10,645 since this time yesterday.
The ministry continued to urge New Zealanders to use the app because it helps with contact tracing.
New Zealand's remaining active case is an Auckland woman in her 50s who was reported as a suspected case on May 1, and who then tested positive on May 21.
She has been in isolation since the start of alert level 4 lockdown in March.
She has had symptoms in the previous 48 hours; a recovered case is someone who has been symptom-free for two days.
The most recent new case was first reported on May 15 - a Christchurch boy aged between 1 and 4 who was linked to the Rosewood rest home.
New Zealanders will find out on Monday when the country will move to level 1, which could be just days later.
Moving to level 1 will continue the debate around reopening borders and operating a transtasman bubble with Australia.
But director general of health Ashley Bloomfield said borders needed to be reopened safely.
Italy has just started lifting restrictions - despite having more than 40,000 active cases and 3000 new cases in the last week.
In New South Wales, Australia, rates of cases were very low, with no new cases Wednesday - but 13 confirmed cases in the week to May 30.
NSW's confirmed cases are around double that of New Zealand's confirmed and probable cases. The state's population is similar to New Zealand and Bloomfield said it was a good comparison.
Earlier this week, Bloomfield joined a regional World Health Organisation call on the topic of how to reopen borders safely.
"We need to remain vigilant to the threat that the virus poses," he said.
"While NZ was looking at a possible return to level 1, this would not be life back to normal. Hand hygiene, keeping a diary of where you've been and staying home when sick were all important."
Despite New Zealand being ahead of other countries in the Covid-19 fight, Bloomfield said there were still lessons to be learnt from other countries as they reopened borders and lifted restrictions - including Italy and the UK.
There have been around 383,000 Covid-19 global deaths reported to the World Health Organisation.
