Genome results show the infection of three Grand Millennium workers who have tested positive for Covid-19 are very closely related, Director-General of Health Dr Ashley Bloomfield says.
However, an audit of the facility has found no significant findings or any cause for concern, The joint head of Managed Isolation and Quarantine Brigadier Jim Bliss, said.
Bloomfield and Bliss made the comments during a media briefing this afternoon.
Last night, it was announced that a third worker at the Grand Millennium MIQ facility in Auckland had tested positive for Covid-19.
They are a close contact of the security guard who was reported with the virus last week and both are genomically linked to Case A, a cleaner from the facility.
Dr Bloomfield told media that complete genomic sequencing shows a very close link with Case A and B. This shows a clear and very direct epidemiological link between the three people.
Dr Bloomfield says Case A and B are genomically identical, which suggests very direct transmission.
"We don't have the direct epidemiological connection between Cases A and B yet, they both worked at the Grand Millennium we know and we're just looking at their shift pattern ... to find that connection."
The latest case - Case C - and their partner are at the Auckland quarantine facility and the partner has returned a negative test, Dr Bloomfield says.
Case C has been in self-isolation during the infectious period, he says. The testing history of Case B is still being investigated, he says. The "period of interest" has been extended.
Dr Bloomfield this morning told RNZ's Morning Report programme that he was awaiting information on the vaccination status of the latest case.
This afternoon he confirmed Cases C and B had not yet received a vaccine but there was no suggestion they were vaccine hesitant.
An opportunity for vaccination had been offered to Case C, Bloomfield says, but they had been unable to attend.
He says vaccination status is private to individuals, but in this case the individuals were told their status would be shared.
Case C has been wanted to be vaccinated but it may have been complicated by being in isolation, Bloomfield says.
Case B had not been tested through March, Bloomfield says. Their first test was 8 April as part of routine testing, and officials are still investigating when Case B was last tested.
"The testing history of Case B is being further investigated."
Bloomfield says 10 out of 11 plus contacts of Case B have now returned a negative Covid-19 test. The 11th is Case C.
Five out of eight close contacts have returned negative results and the remaining three are awaiting their tests, and there are nine casual plus contacts - seven have returned negative tests and the other two are not due yet.
Bliss confirms the audit of the Grand Millennium - the largest MIQ facility - had found nothing of note. He says health and safety of returnees and staff remains a vital priority.
"We are managing a large operation with a diverse workforce as well as conducting an investigation."
It has about 170 staff and 445 rooms, Bliss says, with 347 returnees now in the facility. He says following the notification of a positive staff test at the Grand Millennium a number of steps have been taken.
The technical advisory group will meet tomorrow to make any recommendations for the facility outside of the audit, he says.
Locations of interest
The Ministry of Health has released two new places of interest linked to the Grand Millennium outbreak.
They are Funtech on Queen Street between 5.20pm and 6.25pm on 29 March, and local Barber in Mount Roskill South between 2pm and 4pm on 7 April.
The ministry previously identified Baknervala Dairy, White Swan Mobile, Terminus Dairy, and Bake and Beans, all in the Mount Roskill area, as places of interest.
Bloomfield says the period of interest and some locations of interest now go back to 29 March.
Vaccines
Bloomfield says they remain confident on the progress of the vaccine rollout and more than 110,000 doses have been administered around New Zealand.
He says he expected some workers would be slower to be vaccinated and there will be a whole range of reasons why that is the case.
As the border workforce is changing all the time - staff being rotated in and out - so the total number shifts. As a result, he cannot say how many on the frontline still have not been vaccinated.
Bloomfield says he is satisfied everybody at the border has had the offer and opportunity to be vaccinated.
He says some people have turned down the vaccine and yet are still working on the frontline. The process to shift them into another role is under way.
The end date for border workers refusing the vaccinate would be the end of April.
Bliss says from April 1 every person joining the border workforce has been required to have received at least one dose of the Pfizer vaccine.
Seven new cases in managed isolation
Seven new cases have been reported in MIQ in the past 24 hours, Bloomfield says, bringing the seven-day rolling average of new cases at the border to nine.
There is one new historical case.
Another 17 recoveries bring total active cases to 100, with total confirmed cases at 2227. Three of those were contacts of existing contacts.
There are no new community cases.
A temporary ban on travel from India, which came after a surge in Covid-19 cases being reported at the New Zealand border, officially started at 4pm yesterday and will last until 28 April.
Yesterday there were three new cases of Covid-19 reported in managed isolation and two of them were from India.