At least 30 North Shore Hospital staff had direct contact with a patient who was likely to have been infectious with Covid-19, the Northern Region Health Coordination Centre says.
North Shore Hospital's emergency department and short stay surgical unit have been shut down after a patient treated there earlier has tested positive for Covid-19.
The patient, a young man, is now being treated at Waitakare Hospital.
He had been admitted earlier to North Shore Hospital for an unrelated condition prior to the current lockdown.
Roughly 120 staff may have been in the affected areas at the same times as the patient.
About 107 patients were in the affected areas of the hospital at the same time as the positive patient.
Of these, 29 remain as in-patients, isolating and being tested for Covid-19.
Seventy-eight have been discharged and are self-isolating at home.
Patients are also being transferred to other emergency departments across Auckland.
Associate Minister of Health Ayesha Verrall told Morning Report the hospital shut down the emergency department as it was acting pre-emptively on the possibility that the young man may have been infectious at North Shore hospital before being transferred. That would not become clear until he was able to be interviewed, she said.
North Shore Hospital is diverting new patients elsewhere.
Dr Ashley Bloomfield said this afternoon that the person seen at Waitākere hospital overnight and who was at North Shore is in his late teens.
One of the cases was in the Middlemore hospital emergency department last Friday but left before being seen by anyone. It is not known if they were symptomatic.
The person who was in North Shore hospital did not have covid-like symptoms, Bloomfield says. He was assessed surgically and looked after in the acute surgical unit, which is why those units have been shut down in the meantime. He was not tested at that time.
A doctor at the Northshore Hospital said operations had been hugely disrupted by the stand down of staff.
Julian Fuller, who is also the chief executive of Association of Salaried Medical Specialists, said dozens of staff members had been sent home.
Testing set up at the hospital made it easier for staff to get tested but it also impacted the hospital's capacity, Fuller said.
The emergency department is undertaking a deep clean.
There are now 31 confirmed community cases in Auckland.
Verrall said case numbers, contact tracing and testing will be looked at as Cabinet decides today on any changes to the nationwide lockdown.
Auckland and the Coromandel Peninsula have already been warned they'll probably be at level 4 for at least seven days while the rest of the country was initially locked down for three.
"I think there are some overarching things we can say," Verall said.
"Since going into lockdown [we] have confirmed that this is the Delta variant.
"And we just need to look across the Tasman to see the situation we don't want to be in, which is what's happened in New South Wales where they haven't gone hard and early and as a result have had a prolonged outbreak that's claimed a lot of lives."
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The decision on moving areas outside Auckland and Coromandel out of level 4 would take into account how much testing was occurring in other parts of the country, and whether contacts were identified in the South Island.
"So it really depends a bit on how much information we can have and a degree of confidence that there aren't undiscovered cases there."
Asked if the outbreak of Delta strain is more serious because of New Zealand's low vaccination rates, she said after initial scarce supply of the vaccine the campaign had ramped up.
"We have had to make decisions about allocation of scarce supply in the beginning of the vaccination campaign. But now that we have much more abundant supply we've really ramped up how that's being delivered."
"We have secured the fastest and most effective vaccine with the best safety profile that we can and once we've had stocks we've delivered it incredibly efficiently.
Verral said before lockdown the vaccination programme was going very quickly, and though it had to pivot during lockdown conditions the aim is to get the numbers back on track.
The National Party's Covid-19 response spokesperson Chris Bishop said the country is the slowest in the developed world to vaccinate and should have been further ahead by now.
He says there is real urgency to inoculate frontline workers, supermarket staff and police, and complete port worker vaccinations.
Bishop said police were enforcing the lockdown and should be prioritised. "We have vaccinated more prisoners than we have police officers."
Bishop suggested new ways of delivering the vaccine, now that supply is not a problem, such as health workers going into police stations to give the vaccinations to officers.