MYCOBACTERIUM CHIMAERA INFECTIONS AFTER CARDIOVASCULAR SURGERY: LESSONS FROM A GLOBAL OUTBREAK

Area of Science:

• Infectious Diseases
• Medical Device Safety
• Genomics

Background:

• A global outbreak of invasive *Mycobacterium chimaera* infections has been linked to heater-cooler devices (HCDs).
• These HCDs are used during cardiopulmonary bypass procedures.
• The outbreak highlights a significant risk associated with medical devices.

Purpose of the Study:

• To investigate the source and transmission routes of the *Mycobacterium chimaera* outbreak.
• To understand the challenges in diagnosing and treating these infections.
• To identify lessons learned for medical device regulation and public health surveillance.

Main Methods:

• Outbreak investigations including environmental sampling of HCDs.
• Whole genome sequencing (WGS) of *Mycobacterium chimaera* isolates.
• Analysis of clinical data and patient outcomes.

Main Results:

• HCDs were identified as the source, harboring *M. chimaera* in water circuits.
• Airborne transmission of bacteria to patients during surgery was confirmed.
• WGS data indicated a common-source outbreak originating from an HCD manufacturing facility.
• Clinical infections are often associated with implanted devices, leading to delayed diagnosis and difficult treatment.

Conclusions:

• Existing disinfection methods are ineffective for eradicating *M. chimaera* from HCDs.
• Strict separation of HCD exhaust from operating room air is crucial for prevention.
• Improved pre-market expert review of medical devices and advanced genomic surveillance are essential.