Nontuberculous mycobacteria pulmonary infection in medical intensive care unit: the incidence, patient characteristics, and clinical significance

Abstract

The clinical significance of nontuberculous mycobacteria (NTM) pulmonary infection in medical intensive care unit (ICU) is still unclear. We conducted a retrospective study in the medical ICUs of a medical center in Taiwan from January 1999 to June 2007. Patients with NTM isolated from respiratory specimens within 1 month before or during the ICU course were identified. Those who fulfilled the diagnostic criteria of NTM pulmonary infection were identified and compared with patients with NTM colonization and control subjects who were culture-negative for mycobacteria. Among the 5,378 patients admitted to medical ICUs, 2,866 (53.3%) had received mycobacterial culture for respiratory specimens. NTM were isolated from 169 (5.8%) patients. Of them, 47 (27.8%) were considered NTM pulmonary infection. M. avium complex and M. abscessus were the most common pathogens. Within 100 days after ICU admission, significantly more patients with NTM infection died than those with NTM colonization and control subjects (47 vs. 8 vs. 14%, P < 0.001). Twenty-one (49%) patients with NTM pulmonary infection received anti-NTM treatment, with four experiencing adverse effects. Although statistically insignificant, anti-NTM treatment was associated with prolonged survival for those who died in the ICU and shorter ICU stay for those who survived the ICU course. Our findings suggest that NTM pulmonary infection seems to associate with higher mortality in medical ICUs. Anti-NTM treatment is probably associated with a better outcome. Therefore, keeping a high suspicion when NTM is isolated and using careful consideration when starting anti-NTM treatment should be emphasized.