Non-Tuberculous Mycobacteria. An Emerging Threat?

Area of Science:

• Microbiology
• Infectious Diseases
• Public Health

Background:

• Non-tuberculous mycobacteria (NTM) are increasingly identified in clinical settings.
• Understanding the epidemiology and clinical significance of NTM is crucial for effective patient management.
• This study addresses the growing prevalence of NTM in a specific region.

Purpose of the Study:

• To determine the number and diversity of NTM species isolated in Asturias from 2005 to 2012.
• To analyze the distribution of NTM based on sample source, patient age, and gender.
• To identify clinically significant NTM isolates and associated species.

Main Methods:

• Prospective study of all NTM isolates in Asturias (2005-2012).
• Standardized sample processing according to international guidelines.
• Statistical analysis using Fisher's exact test for contingency tables.

Main Results:

• A total of 3,284 mycobacteria were isolated: 1,499 Mycobacterium tuberculosis complex (MTB) and 1,785 NTM.
• NTM isolation rates increased by 35% while MTB decreased by 21% during the study period.
• NTM were more frequent in men. Mycobacterium kansasii and Mycobacterium avium were most commonly associated with disease, particularly in men.

Conclusions:

• NTM isolation is rising, contrasting with a decline in MTB.
• Both NTM isolation and clinically significant disease were more prevalent in males.
• Only 17.1% of NTM isolates were clinically significant, with M. avium complex and M. kansasii being the primary pathogens.