Mycobacterium chimaera lung infection and empyema in a patient without cardiopulmonary bypass.

Mycobacterium chimaera is a nontuberculous mycobacterium that belongs to the Mycobacterium avium complex. Invasive infections are very rare and have been associated with contaminated heater-cooler water systems used during cardiopulmonary bypass. There is usually a long latency period and patients have nonspecific symptoms that can result in a delayed diagnosis or misdiagnosis. We report a case of M. chimaera infection in a man who presented with worsening shortness of breath and was found to have pleural effusion. The patient did not have any history of cardiopulmonary bypass surgery, which raises concerns about community spread of this rare infection and needs further investigation in the general population. Furthermore, he had a history of sarcoidosis and was on immunosuppressive medications, which might suggest that immunosuppressed patients can acquire this infection without the described risk factors.