Epidemiology and clinical significance of mycobacterial respiratory infections in Central Greece.

Setting: A 750-bed tertiary referral hospital in Central Greece.

Objective: To determine the incidence of non-tuberculous mycobacteria (NTM) respiratory infection based on the isolation of NTM in respiratory specimens, to study their clinical significance and to evaluate the differences in clinical, radiological and demographic characteristics between patients with lung disease caused by NTM and that caused by Mycobacterium tuberculosis complex (MTC).

Design: A 3-year period prospective study to identify patients with positive NTM and MTC respiratory specimens.

Results: Between January 2004 and December 2006, 564 positive NTM cultures from 214 patients and 118 MTC cultures from the same number of patients were collected. The incidence rate of clinically significant NTM lung infection was 0.67, 0.54 and 0.94 cases per 100,000 population, and that of MTC infection of the lung was respectively 5.70, 5.28 and 5.10 cases/100,000 in the three study years. Smoking habits and chronic obstructive pulmonary disease were significant risk factors for NTM disease (P < 0.05 and P < 0.001, respectively).

Conclusions: NTM incidence rates were lower than those reported in the rest of Europe and the USA. Further studies are needed to determine the prevalence and the significant geographic variability of NTM and their clinical significance at the national level.