Patients with non-tuberculous mycobacteria in respiratory samples: a 5-year epidemiological study

Abstract

Background. This study describes the characteristics of patients with positive cultures of non-tuberculous mycobacteria (NTM) in respiratory samples and determines the risk factors that predispose for a reinfection with different NTM species. Methods. Patients with NTM isolates in respiratory samples between 2013 and 2017 were studied. Additionally, risk factors and comorbidities of reinfected patients were analyzed. Results. The study was focused on the 280 patients with NTM isolation (28 were reinfected with at least another species). Mycobacterium avium was the main isolated species. 68% were men. Median age was 73.2. Most remarkable risk factors were: tobacco, COPD and bronchiectasis. Bronchiectasis turned out to be a statistically significant risk factor for reinfection. Only 12 patients (12.4%) were treated. Conclusion. NTM were mainly identified in elderly patients. The most frequent comorbidities were COPD and smoking, whereas the most frequent species was M. avium. Previous bronchiectasis was a predisposing factor for reinfection.