Hamilton General Hospital is dealing with an outbreak on a dedicated COVID-19 unit.
Hamilton Health Sciences declared the outbreak on Saturday after four staff members tested positive for the virus on Unit 8 West.
Officials say the unit remains open and other health care workers who may have been exposed are being tested.
The unit is being thoroughly cleaned and disinfected.
The City of Hamilton is dealing with six other confirmed outbreaks at Aberdeen Gardens Retirement Residence, Alexander Place, Desmond & Peggy Little Retirement Residences, Macassa Lodge, Blackadar Continuing Care Centre, and The Rosslyn.
There are current 631 confirmed cases of the virus in Hamilton.