Health authorities have confirmed a maintenance worker at Rydges Hotel in central Auckland definitely contracted Covid-19 from a guest in the managed isolation facility.
However, the mystery of how the guest infected the worker has not been solved.
The maintenance worker tested positive to Covid-19 on August 13, but his strain of the virus was found to be different to that involved in the big Auckland cluster that has forced the city into a two-week level-3 lockdown.
Instead, it matched the strain of a resident at the Rydges hotel - a woman who flew in from the United States before testing positive for Covid-19 and then being transferred a quarantine facility.
Director general of Health Dr Ashley Bloomfield today confirmed the link between the cases.
"What we do know is that the variation [of the virus] that the maintenance worker has means he caught it from the person who was the case diagnosed in the managed isolation facility and who had travelled from the USA," he said.
The maintenance worker and female guest were not thought to have crossed paths during the woman's stay at Rydges, but a direct infection had not yet been ruled out, such as through a contaminated surface, Bloomfield said.
"It is possible it could have been a direct infection or it is possible there could have been an intermediary," he said.
Authorities were first concentrating efforts on finding any other workers or guests at Rydges with Covid-19.
This would enable them to either confirm the maintenance worker was either infected through another person who had contact with the female guest or to rule this out as a method of transmission.
Authorities had already tested all the staff at Rydges last Friday and these tests came back negative for Covid-19, Prime Minister Jacinda Ardern told media at the 1pm press conference today.
However, a second round of tests had already been done since with the results not yet back.
Health teams were also doing serology tests on the staff. These tests could potentially identify a staff member who was no longer infectious but had earlier had a Covid-19 infection of the same strain as the female guest and consequently establish how the transmission occurred.
If no other Rydges staff are found with the same Covid-19 strain, health authorities cannot rule out that the maintenance worker contracted the virus from the female guest via a contaminated surface.
Infection from a contaminated surface is considered less likely but was possible.
Covid-19 had been shown to survive for up to 72 hours on some surfaces under lab testing and the maintenance worker had been at work at Rydges within 72 hours of the female guest having been there.
Meanwhile, close contacts of the staff member have been put into self isolation to prevent the possible spread of the virus.
Prime Minister Jacinda Ardern said health teams considered it likely there had not been widespread transmission of Covid-19 linked to the maintenance man and that the perimeter of that infection and the Auckland cluster were largely under control.
A Managed Isolation and Quarantine spokesman said investigatons were ongoing.
"There is still no obvious person-to-person connection between the worker and the returnee from the USA but investigations led by the Auckland Regional Public Health continue," he said.
Earlier it was revealed the worker went to work with a cough for two days, but put it down to a pre-existing health condition.
He passed a temperature check at work but tested positive when mandatory testing of staff was introduced late last week.
Prime Minister Jacinda Ardern said that showed how tricky Covid-19 was given it shared symptoms with many other health conditions.
Yesterday, Bloomfield revealed the man was tested on August 13 as part of the mandatory testing regime for all workers at managed isolation and quarantine (MIQ) facilities.
He had his cough on August 11, but passed his daily health checks for two days before the mandatory testing.
One of those days was the day after the current cluster had been notified, and the day that Auckland went back into alert level 3.
He didn't have direct interaction with guests, and maintenance workers had appropriate personal protective equipment, Bloomfield said.
The man's household and workplace contacts who had been tested had earlier returned negative results.
"There are a number of casual contacts from a church service - 56 people have all had contact made except for two, and are in self-isolation and are being tested as well," Bloomfield said.
Megan Woods, the Cabinet Minister in charge of managed isolation, said the maintenance worker's Covid infection is not related to any incidents or systems breakdowns.
"This case highlights how tricky and insidious this virus can be."
Asked why the man wasn't sent home with his cough for two days, Woods said he had passed his daily health check, but those processes were always being looked at with a view to improving them.
Woods said the maintenance worker was not in the same room as the female guest from the US and that this had been confirmed by swipe card-entry data.
"We are not seeing any glaringly obvious points of connection," she said.
Swipe card access has also shown clues about the returnee's movements in the hotel, and Woods said that the returnee mostly stayed in her room.
She said the systems hadn't been in place to regularly test all MIQ staff, even though it was announced as Cabinet's instructions on June 23.
Those staff were now all being tested. Why it hadn't been put in place earlier was a question for the Ministry of Health, she said.
Testing had previously been voluntary, she said, and about 40 per cent of staff at Rydges had been tested prior to the outbreak.
Unite Union general secretary Gerard Hehir today said it was very important to drill down and find what happened with the mystery case at the Rydges Hotel in central Auckland.
In an interview on RNZ today, Hehir described communication between the Government and the Ministry of Health on the testing issue so far as less than ideal.
Hehir said it was particularly concerning no-one has figured out what happened and how.
"Our members are mostly room attendants who clean the rooms in isolation facilities when guests leave, and this maintenance worker has obviously a similar pattern of work to them," Hehir said.
To be fair, he said, the isolation set-up was an extremely complex operation akin to a new prison system.
"This is going to go on for months and months and maybe years. We really need to get the processes down very clear, and testing needs to be done properly and efficiently," said Hehir.
He said his members who work alongside people with Covid want to know when they should be tested, saying they could be the "eyes and ears" of making sure the safety systems work.
Hehir said union members had expected to be tested, but haven't known how often they should be tested, nor did he know of any union members who have resisted being tested.
He said it was unclear for union members what happens if they do not have sick leave, particularly if they have run out or only started work and do not have sick leave.
Hehir said there must not be any disincentive for staff not feeling well or self-isolating if they had been tested or showed any symptoms.
"They are low wage workers. If they think they are going to lose money, then they are less likely to put their hands up and be tested or take a precautionary approach, which is what is needed," Hehir said.
Actions undertaken at the Rydges Managed Isolation Facility
As soon as the positive test was established a series of actions were undertaken immediately at Rydges, including:
• The hotel was put into immediate lockdown on Sunday morning, as soon as the positive test was returned.
• Thorough cleaning of shared areas of the hotel was carried out.
• Close contacts of the staff member identified and put into self-isolation until tested (noting that this staff member was not in a public-facing role).
• Lockdown of guests in hotel lifted once cleaning completed and close contacts identified.
• Close analysis of movements were undertaken, including: Review of CCTV, Review of room entry data to look for connection to cases.
• Genomic Sequence sought from ESR.
• Health advice sought.
• Further testing of all returnees and staff undertaken.
• Confirmation that infection prevention controls have been followed.
• Normal procedures resumed.