Epidemiology of non-tuberculous mycobacterial (NTM) infections in bronchiectasis patients using the US Bronchiectasis/NTM Research Registry (BRR)

<b>Background:</b> The number of cases and deaths from NTM have increased globally, with 2 predominant species, Mycobacterium Avium Complex (MAC) and Mycobacterium Abscessus Complex (MABSC). Management of NTM-Pulmonary Disease (NTM-PD) varies significantly with lack of standardisation due to lengthy multidrug therapy associated with poor tolerability, compliance and outcomes. <b>Objectives:</b> Describe NTM epidemiology, clinical management and outcomes among diagnosed NTM-PD patients <b>Methods:</b> Retrospective cohort study in the US BRR, a registry of adult patients with bronchiectasis and/or NTM covering 2008-2019. History of NTM and/or ≥1positive sputum culture was used for NTM diagnosis. Per physician report, cure was defined as remaining culture negative ≥12m after treatment completion, treatment failure defined as remaining culture positive ≥6m during treatment and recurrence as confirmed disease ≥6m after cure. <b>Results:</b> For 2019, 37.9% (1457/3840) of registry bronchiectasis patients had a diagnosis of NTM infection (MAC/MABSC ratio=5.7:1). Between 2008-2019, 55.1% (555/1008) of MAC-infected patients were treated with antibiotics (vs 62.9% (90/143) for MABSC). Treatment response: <i>*Denominators do not include loss to follow-up, unknown, missing data; the categories are not mutually exclusive</i> <b>Conclusion:</b> The % of registry patients with MAC and MABSC who are treated appear similar, as their outcomes. These findings demonstrate the value of the planned more detailed analysis of treatment pathways and outcomes.