TORONTO -- A COVID-19 outbreak has been declared at Toronto's Sunnybrook Hospital.

In a news release issued on Monday, Sunnybrook said that they identified a patient with COVID-19 as part of their "normal surveillance," which led them to test all the patients in the affected unit.

"In total we have identified four cases, and two of those patients remain at Sunnybrook. All other patients on the unit are negative for COVID-19," the hospital said.

As a result, Sunnybrook said that the unit is currently closed to new admissions and that no other positive cases have been identified at this time. 

"When an outbreak is declared, affected patients are isolated immediately, and control measures are put in place including staff being dedicated to the unit and following strict precautions, increased surveillance, testing and enhanced cleaning measures," Sunnybrook said.

Sunnybrook said their facilities remain open and safe for patients and visitors. Clinics and procedures are also scheduled to continue as usual.

A spokesperson for Toronto Public Health (TPH) said that they are aware of the situation and that "appropriate precautions and outbreak control measures are in place."

There have been 99 outbreaks reported in various hospitals across Ontario since the beginning of the pandemic. 

Three of the outbreaks are considered active.