Screening non-tuberculous mycobacteria in patients with bronchiectasis

The isolation of non-tuberculous mycobacteria (NTM) has been described in 2 to 63% of bronchiectasis patients, depending on the country and the criteria for searching. <b>Aim:</b> To determine the prevalence of NTM isolations in a cohort of patients with bronchiectasis over a 20-year period. <b>Method:</b> A single-centre retrospective cohort study of adults with non-cystic fibrosis bronchiectasis seen between January 1998 and December 2018. None had a previous history of NTM. Since 1998 our protocol has required that a mycobacterial culture be ordered for all patients with sputum production at the initial visit, annually, during hospitalization, in the event of poor clinical control, and before initiating the long-term use of macrolides. <b>Results:</b> 290 out of 358 patients were included (175 women (60%), mean age at last control 66.2±16.3 years, follow-up 6.3±5.5 years, 1.2 mycobacterial cultures per patient per year. 15 patients (5.2%) had one or more positive cultures for NTM, 7 women, mean age 69.6±16.6 yrs, follow-up 9.6±6.6 yrs. 2 women had M.avium complex (MAC) pulmonary infection, which was eradicated in one case but persists in the other 20 years after treatment. Persistent colonisations of M.abscessus were detected in 2 men after 10 years: both cases were treated and colonisation was eradicated in one whereas the other patient died. MAC was intermittently isolated in 3 patients. On single occasions MAC was isolated in 3 patients, M.gordonae in 3, M.peregrinum in 1 and M.fortuitum in 1 M.tuberculosis was incidentally isolated in 3 patients. <b>Conclusion:</b> NTM isolations are low in our area. As well as revealing the true prevalence in each area, routine screening for NTM in bronchiectasis permits early detection and treatment.