Outcomes of pulmonary Mycobacterium abscessus infection

Background: Treatment of Mycobacterium abscessus pulmonary disease (PD) is challenging with frequent side effects and uncertain rates of success. Methods: We performed a retrospective review of all patients at our center with at least one respiratory sample positive for M. abscessus between 2014 and 2019. Electronic health records were reviewed to determine factors associated with M. abscessus infection and clinical outcomes. Results: Thirty-seven patients were identified including 24 with cystic fibrosis (CF), 10 with bronchiectasis, two with chronic obstructive PD (COPD), and one with asthma. American Thoracic Society/Infectious Diseases Society of America criteria for nontuberculous mycobacteria PD were met in 21/37 (56.8%) of cases. Evidence of Aspergillus lung disease was noted in 18 (75.0%) CF patients compared with 3 (23.1%) non-CF patients (P = 0.005). Induction therapy for M. abscessus was given to 22/37 (59.5%) patients (18/24 [75%] with CF and 4/13 [30.8%] without CF). Median duration of induction therapy was 6 weeks (range 3-12). Maintenance antibiotic therapy was prescribed to 17/22 (77.3%) of treated patients. Culture conversion was seen in 15/24 (62.5%) of CF patients compared with 3/13 (23.1%) in the non-CF group (P = 0.034). Culture conversion occurred in 10/22 (45.5%) of treated patients compared with 8/15 (53.3%) untreated patients. Three patients (8.1%) died during follow-up: one with CF and two with COPD. Conclusions: Culture conversion following isolation of M. abscessus from respiratory samples not only is more common in CF than in patients without CF but also frequently occurs spontaneously in both groups. Targeted treatment for M. abscessus did not clearly impact rates of culture conversion.