Mycobacterium Chimaera Infections After Open Heart Surgery

Mycobacterium chimaera is a nontuberculous mycobacterium which is genetically and phenotypically similar to other Mycobacterium avium complex species. It has been identified as a contaminant of LivaNova Sorin Stockert 3T heater-cooler units used in conjunction with cardiopulmonary bypass in open heart procedures and extracorporeal membrane oxygenation therapy. It has caused postoperative infections which are difficult to diagnose and often present after several months due to the organisms innate slow replication. The late presentation occurs after the organism already has had time for systemic dissemination and can lead to multiorgan involvement including endocardial, pulmonary, hepatic, renal, and bone marrow infiltration. It causes granulomatous inflammation but initial symptoms tend to be nonspecific with fevers, chills, and shortness of breath as the most common complaints. Antimicrobial treatment involves three or four drug regimens, and surgical management is frequently required for full eradication. Unfortunately, clinical outcomes remain poor with a high mortality rate. Early diagnosis is key in treatment of this infection.