A staff member at Auckland Hospital has tested positive for Covid-19.
The Auckland DHB says the fully-vaccinated worker tested positive on Saturday.
The DHB says it then "immediately activated plans for this situation to prevent the spread of the virus within the hospital".
"We have robust infection prevention and control measures in place, which includes mask wearing on-site. We work closely with occupational health and public health to keep everyone safe, as well as continue to provide high-quality care to people that need it.
"We worked quickly to identify all contacts and carry out testing on-site for patients and staff. We have had no further positive results reported for patients and staff from this exposure so far," said Alex Pimm, Auckland DHB's Covid-19 incident controller.
"The advice for Auckland DHB patients and whānau who have been at our Auckland City Hospital campus is that they do not need to take action unless they are contacted by public health or the DHB. As always, anyone who has any Covid-19 symptoms at any time should get a Covid-19 test and stay at home," Pimm said.
"The public can be assured that if they need our care, they will be safe in our hospitals."
The positive result follows a Covid scare at the hospital after a mother with the virus was able to visit her dying baby at the neonatal intensive care unit (NICU) on Thursday.
The baby was born prematurely and did not have Covid. It is understood its parents were able to be present as their baby passed away.
No other babies, parents, and staff have tested positive.
The Nurses Organisation said losing a child in such circumstances was extremely sad and difficult, and a spokeswoman extended her condolences to the family.
However the union was also concerned with how the visits were communicated to staff, and says this reflects a wider problem around Covid protocols at the country's biggest hospital being made with little consultation with frontline workers.
NICU nurses were told of the impending visit about 15 minutes before the couple arrived late on Thursday night, the Herald understands.