No new cases of COVID-19 have been detected in connection to the managed isolation worker who tested positive for the virus on Monday, COVID-19 Response Minister Chris Hipkins announced.
The minister and Director-General of Health, Dr Ashley Bloomfield, gave the updates on Case A, the cleaner at Auckland's Grand Millennium Hotel who contracted COVID-19, during a press conference on Wednesday afternoon.
"This could indicate the first result was a false positive or that it was an early, or fleeting, mild infection that has now passed," Dr Bloomfield added.
The relative will undergo further serology testing to ensure any changes in antibody levels are detected, and will remain classified as under investigation.
They are currently staying at Auckland's quarantine facility, the Jet Park Hotel, while investigations continue.
Addressing revelations that a St Lukes kindergarten and the Quay St Countdown were closed on Tuesday after being visited by Case A and their relative respectively, Dr Bloomfield reiterated a Countdown in Mt Roskill remains the only location of interest.
Some businesses visited by Case A have not been classified as locations of interest due to a variety of reasons, Dr Bloomfield said, such as the correct public health measures were followed, or health officials have already made contact with those who may have been exposed to the affected individual. He also acknowledged that in some instances, no people were at risk.
"The case we have been dealing with this week [poses] a very low exposure risk," Hipkins reiterated.
"The case had not really been out and about in the community in the few days before they tested positive," Dr Bloomfield added.
"The only place of interest is the Countdown Mt Roskill, between 3pm and 3:15pm on Saturday, March 20."
The cleaner used their NZ COVID Tracer app "meticulously", which aided health officials with rapid contact tracing efforts.
Dr Bloomfield also repeated earlier information regarding the results of genome sequencing, which found a clear link between Case A and their workplace. The cleaner has been matched to a recent returnee who stayed at the Grand Millennium between March 13-15, before the worker received their second jab of the Pfizer-BioNTech vaccine. The new arrival tested positive on the first day of their stay and was later transferred to the Jet Park Hotel.
"This provides a high level of reassurance that Case A's infection was picked up at their workplace rather than elsewhere in the community," Dr Bloomfield said.
Genome sequencing also confirmed Case A is carrying the B.1.1.7 mutation of the virus, also known as the UK variant - a more transmissible strain understood to have an increased mortality rate than earlier variants.
Three new cases of COVID-19 have been picked up in managed isolation facilities, all of which arrived on March 21. The returnees travelled from Ethiopia, India and Indonesia respectively, the latter two via the UAE and Singapore. All three returned positive results due to routine testing at either day zero or day one, and are quarantining in Auckland.
Three previously reported cases have recovered, bringing the total number of active cases to 67.
To date, New Zealand has recorded a total of 2114 confirmed cases.
Since January 1, 2021, 41 out of a total of 302 cases have been classified as historical infections.