Extremely Low Risk of Exposure to Bacteria Through Open Heart Surgery Identified

Approximately 11,500 AHS adult and pediatric patients to be notified

EDMONTON – Alberta Health Services (AHS) is notifying about 11,500 former open-heart surgery patients of an extremely low risk of infection related to potential exposure to bacteria during their procedure.

The Federal Drug Administration (FDA) and Centers for Disease Control (CDC) in the U.S., as well as Health Canada, have reported a potential risk for Mycobacterium chimaera infection associated with certain heater-cooler units, which are used to warm and cool blood during adult and pediatric open heart surgery.

AHS has used and does use these heater cooler units at the Foothills Medical Centre in Calgary and at the Mazankowski Alberta Heart Institute and the Stollery Children’s Hospital in Edmonton.

“We are releasing this information proactively to share details about the potential risk of exposure to M. chimaera bacteria as well as to reassure patients and families that there is an extremely low risk of infection in those who may have been exposed. No infections have been identified to date in any AHS cardiac patients,” said Dr. Mark Joffe, AHS Senior Medical Director, Infection, Prevention and Control.

“As always, patient safety is our first priority. Our sites follow manufacturer instructions for use to clean and maintain these machines. At all sites, we have implemented additional safety measures to further minimize risk.”

M. chimaera infections cannot be spread by person-to-person contact. Infections grow slowly and may take months or even years to develop. Symptoms can be subtle, but will generally progress over several weeks and may include:

  • Fever
  • Unexplained, persistent and profuse night sweats
  • Unintentional weight loss
  • Muscle aches
  • Fatigue
  • Redness, heat or pus at the surgical incision site


“It’s important for patients to understand that symptoms are far more likely to be caused by other health conditions or short-lived bacterial or viral infections than M. chimaera,” said Dr. Joffe. “The risk of M. chimaera infection is extremely low but it is important to consult with your doctor if symptoms persist for more than a couple of weeks and you feel that your health is declining.”

Over the coming days, AHS will mail notifications to Alberta physicians and discharged open-heart surgery patients who may have been exposed to M. chimaera during their procedure. The public notification will include adults and parents or guardians of pediatric patients.

AHS is monitoring the situation very closely and will continue to follow all Health Canada guidance and direction related to the use of heater cooler machines.

Individuals looking for more information can contact Health Link at 811.

Alberta Health Services is the provincial health authority responsible for planning and delivering health supports and services for more than four million adults and children living in Alberta. Its mission is to provide a patient-focused, quality health system that is accessible and sustainable for all Albertans.