Thirty-six patients and some visitors are considered potentially exposed to the latest Covid-19 case at Middlemore Hospital.
The woman went to the emergency department yesterday morning with an issue unrelated to Covid, and said they had had no exposure to the virus, no symptoms, and had not been at any locations of interest.
She spent time in the Emergency Department and Adult Short Stay ward before deciding to go home, but a Covid-19 test taken at the hospital later came back positive. The woman is now in managed isolation.
Middlemore Hospital chief medical officer Dr Peter Watson told Morning Report the person spent under two hours at the hospital.
Thirty-six patients and a small number of visitors were identified as potentially exposed, he said.
"We are contacting all of those and they will have to go into isolation and be followed up."
Most had been discharged and were being followed up at home by Auckland Regional Public Health and 17 remain in hospital and in isolation.
"Fortunately, being the emergency department, everyone was wearing the appropriate PPE and appropriate masks so no staff have had to be stood down."
The hospital has more than 200 people a day turning up at its busy emergency department so is being vigilant, he said, and in this case gave a swab even though it wasn't indicated by screening.
"The other thing though it really is calling out is the need for everybody in South Auckland who's been potentially to a place of interest, with a contact, or has any symptoms whatsoever to make sure you get swabbed."
Last weekend, Middlemore staff were stood down and patients isolated and tested after a Covid-infected man spent a day on a ward.
The patient had reported only abdominal pain, and that was subsequently added to the checklist of symptoms that staff screen for.