Mycobacterium abscessus complex: Natural history and treatment outcomes at a tertiary adult cystic fibrosis center.

Background: Mycobacterium abscessus complex (MAbsC) is a significant management dilemma when taking care of patients with cystic fibrosis (CF).

Methods: We undertook a retrospective cohort analysis of all CF patients in whom MAbsC was isolated from 2005 to 2014. The natural history of MAbsC was determined and clinical factors examined in an attempt to predict transient compared to persistent colonization.

Results: No correlation was found between recurrent MAbsC isolation and clinical factors such as body mass index, respiratory function, or age. Over two-thirds of our cohort cleared MAbsC colonization with no intervention and no consistent effect on lung function was identified. Four CF patients were initiated on treatment with only one successful outcome.

Conclusion: This analysis demonstrates there are no clear predictors of those CF patients who will become persistently colonized with MAbsC and that a significant proportion will spontaneously clear carriage. As treatment success rate is poor, more work is urgently required in improving patient outcomes.