Murphy said sister hospitals St Augustine's and Kingsway were closed for emergencies as well as the admitting of patients.
Netcare announced on Wednesday that a patient had tested positive for Covid-19 at Kingsway.
It subsequently emerged that six health care workers had also tested positive for the virus.
At St Augustine's, 66 people — including health care workers had tested positive. Four deaths related to the virus were recorded at the hospital.
“EMS service providers are aware that the hospitals' emergency departments are closed, and will therefore transport people needing medical care from the scene of the accident or incident directly to another appropriate emergency department.
“People who make their own way to an emergency department will also have to visit an alternative facility,” said Murphy.