An outbreak of COVID-19 has been declared at Credit Valley Hospital in Mississauga after four patients in one unit tested positive for the virus.

Trillium Health Partners (THP), a hospital which encompasses three sites including Credit Valley Hospital, said in a statement Tuesday that it has taken "immediate precautions" to protect patients and staff. The outbreak occurred in Rehab 1D unit, according to its website.

The hospital, located west of Toronto, is relocating the four patients with the virus to a unit exclusively intended for patients with COVID-19. It is identifying anyone else who may have been exposed to the virus, and it is monitoring all other patients for symptoms, Trillium Health Partners said.

It is also working closely with Peel Public Health officials.

"Our top priority is the safety of patients, our health care workers and the community," Trillium Health Partners said in the statement.

No longer permitting visitors

"As we continue to see community spread of COVID-19, THP remains vigilant and is actively preparing measures to respond to additional cases and outbreaks."

The outbreak comes after Trillium Health Partners said on March 20 that is no longer accepting visitors at any of its sites.

It said limited exceptions are being made for visitors of patients in the following categories: those at the end of life; who are critically ill; are under age 18; or women in its birthing suites.

"In order to provide safe, high-quality care, we must reduce the transmission of illness as best we can to protect all patients, including those most vulnerable and at risk. We will continue to re-evaluate our infection prevention and control measures and make changes as necessary," the hospital said on its website.

The outbreak at Credit Valley Hospital comes after Trillium Health Partners said on March 20 that is no longer accepting visitors at any of its sites. (Tina Mackenzie/CBC)

On Tuesday, Trillium Health Partners announced on Twitter that it has modified access to entrances at Credit Valley Hospital to reduce congestion and increase the ability of staff and patients to practise physical distancing.

On the weekend, Peel police, paramedics and firefighters staged a parade of vehicles, with lights on and sirens flashing, in front of Credit Valley Hospital as a show of support for front-line health care workers.