Continued vigilance encouraged for M. chimaera infection in open heart patients

EDMONTON – Alberta Health Services (AHS) is notifying physicians to consider exposure to M. chimaera bacteria as a possible cause for prolonged illness in patients who underwent cardiac surgery from 2012 to 2017.

A case of M. chimaera infection was recently confirmed in a patient who underwent open heart surgery several years ago.

“We are reminding physicians about the importance of considering the potential risk of exposure to M. chimaera bacteria in cardiac surgery patients who are experiencing persistent, unexplained symptoms,” said Dr. Geoffrey Taylor, AHS Senior Medical Director, Infection, Prevention and Control. “At this time, we still believe the risk to be very low but M. chimaera can be difficult to diagnose and symptoms can take up to five years to appear.”

Symptoms can be subtle but will generally progress over several weeks and may include fever, persistent and profuse night sweats, unintentional weight loss, muscle aches and fatigue. Treatment includes a prolonged course of multiple antibiotics and often, repeat surgery to remove infected tissue.

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

At that time, AHS notified approximately 11,500 former open-heart surgery patients of the low risk of potential exposure to bacteria during their procedure. There have been seven documented cases of M. chimaera infection in Alberta since this global outbreak was identified in post-operative cardiac surgery patients. Five of these patients have died.

AHS previously used the implicated heater-cooler units at the Foothills Medical Centre in Calgary and at the Mazankowski Alberta Heart Institute and Stollery Children’s Hospital in Edmonton. The heater-cooler units were replaced in 2017 with redesigned models approved by Health Canada.

M. chimaera infections cannot be spread by person-to-person contact.

Individuals wanting 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.