Mycobacterium xenopi pulmonary disease - Epidemiology and clinical features in non-immunocompromised patients

Objectives: The genus Mycobacterium has more than 120 well-characterized species. Although the incidence of tuberculosis has decreased over the studied period, other, non-tuberculous mycobacteria (NTM) are isolated more often. Since, Mycobacterium xenopi is the most frequent NTM isolate in Croatia we studied its epidemiology and clinical relevance. Methods: We performed a retrospective study over a 25-year period determining epidemiology, radiological findings and clinical importance of M. xenopi infection, obtaining data from archives in health care institutions from all over the country. Results: We detected 40 patients with a positive isolate of M. xenopi. Twenty-four patients met American Thoracic Society criteria for pulmonary disease. Eighteen (90%) of treated patients were mate, on average 61.7 years old. Nineteen (95%) patients lived in towns. Most of them had comorbid disease, 18 (90%), with chronic obstructive pulmonary disease (COPD) being the most frequent, found in 11 (55%) patients. All patients were immunocompetent. We found COPD as the most frequent comorbid disease in the group of patients with worse treatment response (n = 8; 80%), white in patients with good treatment response COPI) was less frequent (n = 3; 30%). Differences in the proportions of patients with COPD were significant (p = 0.037). Conclusion: In patients with M. xenopi pulmonary infection, COPD is a predisposing condition, and as a comorbid disease, is an important prognostic factor for treatment response. (C) 2009 The British Infection Society. Published by Elsevier Ltd. All rights reserved.