One man in Waitakere Hospital has tested positive for Covid-19, and could have been infectious during his stay at another hospital earlier this week.
The man, who is in his 20s, was in North Shore Hospital earlier this week with an unrelated condition. The news was confirmed by the Prime Minister's Office and the Ministry of Health early Friday morning.
North Shore Hospital is standing up testing for its staff and patients. The hospital will be closed on Friday.
"Given the incubation period of the virus, the DHB has assumed that the person could have been infectious during the admission to North Shore Hospital," the Director-General of Health Dr Ashley Bloomfield said in a statement.
He said staff who have been affected will be stood down and told to follow public health advice. Patients who may have been exposed to the virus will be isolated and tested in the hospital.
A Northern Region Health Coordination Centre spokesperson, which co-ordinates the Auckland region's Covid-19 response, said 30 staff had direct contact with the patient.
The 30 staff members are part of a group of about 120 that were rostered on at North Shore Hospital at the time the patient was there.
Additinally, approximately 107 patients were in the affected areas at the same time as the patient with Covid-19, the spokesperson said.
Of these, 29 remain in the hospital. They are being isolated and tested for Covid-19. Another 78 have been discharged and are self-isolating at home and are being followed-up by public health officials.
Bloomfield said people who need emergency care are being diverted from North Shore Hospital and Short Stay Surgical Unit on Friday.
"The DHB has taken immediate action to close the North Shore Hospital Emergency Department and Short Stay Surgical Unit to new admissions," Bloomfield said.
"Diversions to other hospital EDs are in place as the DHB this morning contacts staff and patients who may have been exposed to Covid."
Patients already discharged will be followed-up by public health officials.
Associate Health Minister Ayesha Verrall told Breakfast the DHB was taking a "precautionary approach" with the decisions it had made.
When asked how serious the situation was, she said: "These sorts of scenarios are ones that we plan for."
She said a detailed assessment would come today as to whether patients needed to continue being diverted. Genome sequencing into the man's infection would also begin.
Contact tracing interviews will also be carried out on Friday to see if the man had any connection to the current outbreak, Verrall said.
Deep cleaning at North Shore Hospital will take place on Friday.
Officials say any further details on any other new cases would be reported at 1pm.