The London Health Sciences Centre (LHSC) in London, Ont., has sent letters to approximately 2,200 adult open-heart surgery patients warning them of the possible risk of bacterial infection from surgical equipment.

In a press release issued Tuesday, the hospital explained that patients may have been exposed, through contaminated heater-cooler units, to bacteria which can cause a mycobacterium chimaera infection. The medical devices, which are used to regulate blood temperature during open-heart surgery, have been the subject of safety alerts issued by Health Canada, Public Health Ontario, and the U.S. Federal Drug Administration and Centres for Disease Control.

The LHSC stressed that patients’ risk for infection is “extremely low.”

“Thankfully, the risk of infection is less than one per cent and the risks of not having the surgery far outweigh the risk of infection,” the director of infection prevention and control at LHSC, Dr. Michael John, said.

According to Health Canada, the mycobacterium is typically not harmful, but in rare cases, it can cause infections in patients with compromised immune systems, chronic diseases or health conditions. Because symptoms can take months or even years to manifest, diagnosis may be difficult. Additionally, there isn’t a screening test for individuals to see if they have been exposed to the bacteria.

The bacteria are naturally found in soil and water and can be inhaled. The open-heart surgery patients may be exposed to the bacteria when condensation produced from the machine settled in their open chest during the procedure.

The hospital advises patients to monitor themselves for the following symptoms:

  • Night sweats
  • Muscle aches
  • Weight loss
  • Fatigue
  • Unexplained fever and redness, heat, or pus around the sternal surgical incision

The LHSC also suggested that anyone who has shown symptoms or who has been diagnosed with sarcoidosis since their surgery should contact their doctor or call the hospital at 1-844-358-1050.

There have been no reported cases at LHSC and John told CTV London on Tuesday that the hospital has taken extra precautions to prevent possible infection.

“The machines that we have are newer and were purchased after the time this problem was identified,” John said. “We comply with all the disinfection protocols that the manufacturer recommends and our machines have also always been on the edge of our ORs with the fans facing away from the operative field.”

This is not the first time a Canadian hospital has issued a warning about the risk of mycobacterium chimaera infection from the heater-cooler systems to their patients. At the end of October and beginning of November, a number of hospitals in Quebec and one in Manitoba notified thousands of patients about the possibility of infection.

The medical device linked to the infection is used in hospitals across Canada, the U.S. and in Europe. It’s believed the bacteria were present in the equipment during manufacturing, but went unnoticed.