MONTREAL -- The Lachine Hospital is dealing with a significant outbreak of COVID-19, with 22 patients and 14 staff so far testing positive.

The first cases were confirmed on Sunday, on one floor of the hospital. Admissions were paused to that floor (the hospital did not want to name which floor it was to preserve patients' privacy).

A spokesperson told CTV News on Thursday that it's asking the public not to use the hospital's emergency room.

Two floors are now involved -- one a regular care ward and one that has intensive care -- and all patients who have tested positive have been transferred to other hospitals "so the Lachine Hospital can remain a cold establishment," said the spokesperson.

All other patients who may have been exposed are "under preventative isolation" and are being monitored for symptoms, with periodic testing.

Contact tracing is underway, and public health is still trying to determine what likely caused the outbreak. 

All the health-care workers who were exposed to infected patients have been tested, and the 14 who tested positive are, of course, not at work.

Various hospital services have "gradually resumed" since Tuesday, the hospital said, including outpatient clinics, consultations with specialists, radiology exams and blood samples.

The exception is cardiac ultrasound, which is still on hold.