All elective surgeries will be suspended until the end of next week at a private hospital in Perth after black mould was found circulating in its air conditioning.
Mount Hospital confirmed on Thursday that routine testing had discovered the presence of black mould "in some hospital air intakes", and the hospital was taking precautionary measures in affected areas.
The hospital said the mould presented a "relatively low health risk for healthy individuals", but the risk to immunocompromised people may be elevated.
Patients were moved out of the hospital's intensive care unit, coronary care unit and one other ward.
In a statement on Friday, the hospital said it was working with authorities and keeping them informed of its progress with air quality testing and monitoring, along with deep cleaning of the affected air ducts.
"At this stage, the time required to complete the required testing, cleaning and receive confirmed test results means elective surgery at Mount will be paused until the end of next week," the statement said.
"We apologise to our patients for the inconvenience caused. We are contacting affected patients directly to advise them of the situation and will work with their doctor to reschedule their admission as soon as possible."
Patients seek treatment elsewhere
A patient who was receiving treatment at Mount Hospital on Thursday told the ABC some patients voluntarily left the hospital to seek treatment elsewhere.
The hospital said it had advised all patients and staff of the situation.
"We are taking all appropriate steps to ensure their ongoing safety while these remediation works are underway," the hospital said on Thursday.
A Department of Health spokesperson said the department was aware of the issues at Mount Hospital and were monitoring its actions.
The bacteria that causes Legionnaires' disease – legionella – was also detected in the Mount Hospital's drinking water in October 2022.