Reemergence of Mycobacterium chimaera in Heater–Cooler Units despite Intensified Cleaning and Disinfection Protocol

Peter W. Schreiber; Stefan P. Kuster; Barbara Hasse; Cornelia Bayard; Christian Rüegg; Philipp Kohler; Peter M. Keller; Guido V. Bloemberg; Francesco Maisano; Dominique Bettex; Maximilian Halbe; Rami Sommerstein; Hugo Sax


Emerging Infectious Diseases. 2016;22(10):1830-1833. 

In This Article

Abstract and Introduction


Invasive Mycobacterium chimaera infections after open-heart surgery have been reported internationally. These devastating infections result from aerosols generated by contaminated heater–cooler units used with extracorporeal circulation during surgery. Despite intensified cleaning and disinfection, surveillance samples from factory-new units acquired during 2014 grew nontuberculous mycobacteria after a median of 174 days.


Mycobacterium chimaera is an emerging pathogen causing disastrous infections of heart valve prostheses, vascular grafts, and disseminated infections after open-heart surgery.[1,2] Growing evidence supports airborne transmission resulting from aerosolization of M. chimaera from contaminated water tanks of heater–cooler units (HCUs) that are used with extracorporeal circulation during surgery.[3,4] HCUs were previously associated with surgical site infections caused by nontuberculous mycobacteria (NTM).[5] We describe the colonization dynamics of factory-new HCUs with NTM during regular use.