Thousands of patients who had open heart surgery at the London Health Sciences Centre are being notified they could be at risk of a bacteria infection from the procedure.
The hospital said the infection risk is extremely low. About 2,200 former open heart surgery adult patients have been notified by letter.
Patients have been advised they could be at risk of a Mycobacterium chimaera infection, which can take months or even years to develop.
Dr. Michael John, director of infection prevention and control at LHSC , said the issue is worldwide and has been linked to units manufactured in Germany which heat and cool blood during open heart surgery. LHSC has been using the units since January 2015.
There have been no diagnosed cases in London.
John said the bacteria, which is found in water and soil but is not contagious, is unusual because of the lengthy incubation period. The risk of infection from the bacteria is pegged at less than one per cent.
Patients are being asked to monitor for the following symptoms: