A new exposure event at Middlemore Hospital has meant 21 staff have had to be stood down.
The event comes after a patient returned a positive Covid-19 test result on Monday.
The case visited the hospital's Emergency Department on Friday for a non-Covid-19 related issue where they were assessed and admitted.
The patient was asymptomatic and answered no to all Covid-19 screening questions.
The patient then developed a cough on Sunday, was tested, and on Monday returned a positive test result.
Health officials said 40 patients had been identified as contacts as a result of the exposure event. Of these, 15 are inpatients while the remaining 25 are being followed up by the Auckland Regional Public Health Service.
Thirty-four staff have also been identified as contacts. Of these, 21 staff have been stood down with testing plans.
"While there have been a number of exposure events at Middlemore Hospital, this is not unexpected as there are a number of subclusters in South Auckland, for which Middlemore is the local hospital," the Ministry of Health said.
The Ministry of Health said to date, no exposure events at Middlemore Hospital had resulted in Covid transmission to other patients or staff.
Five hospital staff in Auckland have tested positive for Covid-19 since cases emerged over the weekend.
Two Auckland City Hospital staff returned positive tests on Monday morning after another staff member tested positive over the weekend, the Health Ministry said in a 1pm statement.
All three were fully vaccinated, says Auckland District Health Board's Covid-19 incident controller Alex Pimm.
Initial investigations show no links to the Neonatal Intensive Care Unit (NICU) parent case or to each other. "It appears the Covid infections were community-acquired," said Pimm.
Of the three, two were tested at a community testing site while one was tested as part of routine workplace surveillance.
Auckland City Hospital has now identified all contacts of the staff member who tested positive over the weekend to carry out testing on-site for staff and patients.
The advice for Auckland DHB patients and whānau who have been at their sites is that they do not need to take action in regard to these cases unless they are contacted by public health or the DHB.
"Ninety-eight per cent of our staff have had at least one dose of the Covid-19 vaccine, which we know reduces the likelihood of onward transmission as well as serious illness.
"With more than 12,000 staff, the DHB is one of the biggest employers in Auckland so it is not unexpected that there will be staff members who acquire Covid within the community.
"The public can be assured that if they need our care, they will be safe in hospitals," said Pimm.
At North Shore Hospital two staff members returned positive results on Monday.
Both are fully vaccinated and work at the dialysis unit adjacent to the hospital where a patient was reported as Covid-positive on Saturday.
No direct link between these cases has been established and investigations continue, says the hospital's Covid-19 executive lead Tamzin Brott, but the hospital is taking a conservative approach while recognising the need to keep life-saving services running for renal patients.
Eighteen staff were identified as close contacts and stood down from work as an initial precaution and pending further investigation.
The dialysis unit remains open but there are measures in place to manage potential risks to patients and staff.
This includes the mandatory use of personal protective equipment (PPE) and intensive cleaning between each group of patients, and rapid antigen testing for staff before each shift.
"Even with these precautions in place, we can expect staff in the unit will be feeling anxious," said Brott, acknowledging the team's commitment to renal patients.
The Waitemata DHB employs almost 9000 people and is looking at further controls to reduce the frequency and impact of Covid exposure in their services, Brott said in an update to hospital staff.
"As the number of Covid cases increases in the community, we should recognise that the likelihood of our services and staff encountering positive cases also rises."
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