CALGARY -- The COVID-19 outbreaks continue to grow at the Foothills Hospital with three more people testing positive for the virus and another unit upgraded to an outbreak.

Alberta Health Services (AHS) says two patients and one health-care worker tested positive for COVID-19 since yesterday. Sixty-three cases are now linked to the outbreaks, including staff, patients and two visitors to the hospital. Four patients have died since the outbreaks were first reported.

Several of the six units affected are in the cardiac ward and AHS confirms some new referrals to the Cardiac Catheterization Lab (CCL) are being sent to hospitals in Edmonton due to staff shortages at the Foothills.

Health officials say 290 workers have been told to isolate due to possible exposure to the virus. The union representing some of the workers at the hospital say staffing was an issue before the pandemic hit, and this just makes the situation more stressful for people working there.

"They are terrified," said Bobby-Joe Borodey with the Alberta Union of Provincial Employees.

"They go to work every single day scared, not knowing if the outbreak has been contained or will grow larger. And, you know, the health and safety of themselves and more importantly their families is what’s constantly on their minds all the time."

AHS says surgeries scheduled for Wednesday went ahead as planned, but 29 were postponed earlier in the week. A majority of the hospital’s procedures are continuing and all of the hospital’s services are offered, officials say.

Patients and staff in the units affected are screened twice daily and more than a thousand COVID-19 tests have been administer on-site since the outbreaks started.