Director-General of Health Dr Ashley Bloomfield says the unlinked COVID-19 cases in New Zealand's current outbreak means there may be undetected cases in the community.
There are 34 cases yet to be epidemiologically linked out of the 922 total in this outbreak. Of these 34, eight of the cases announced on Sunday are unlinked.
When these unlinked cases are found, targeted testing is done in communities on both symptomatic and asymptomatic people, Dr Bloomfield says.
"That's really important for us to just see if there are any other cases out there. The volume of testing is reassuring but we need to keep that going over the next few days," he said on Sunday.
Prime Minister Jacinda Ardern says while these cases are initially unlinked, a connection is sometimes found by the end of the day. When this doesn't happen, genome sequencing is undertaken which "takes a bit more time".
"The vast majority of these cases, we know where these are coming from, but you always want to do more to assure yourself, because we are still seeing some coming through that are unlinked that are taking us time to make a connection, and that presents risk," she says.
But Dr Bloomfield says despite these unlinked cases, there is "no widespread community transmission" in Auckland.
"We have seen a few cases over the last week or so which, as the Prime Minister has said, have taken us a bit of time to link, therefore we are assuming there may be other undetected cases," he says.
"Hence why for the last six days or a week, there's been very targeted testing in communities, not just of symptomatic people but of asymptomatic people."
Auckland has been in an alert level 4 lockdown for almost four weeks after a case was discovered in the community in mid-August. The rest of New Zealand has since moved up to level 2.
An update on the city's alert level is set to be made on Monday.
