Nontuberculous mycobacteria among patients who are suspected for multidrug-resistant tuberculosis - Need for earlier identification of nontuberculosis mycobacteria

BACKGROUND: In this study, we intended to find the prevalence of nontuberculosis mycobacteria (NTM) among patients who are referred as suspected multidrug-resistant tuberculosis (MDR-TB) cases to the only referral center in Iran. METHODS: All patients referred to our center in 2002-2006 as MDR-TB with histories of treatment with standard and CAT II World Health Organization regimens were included in the study. Sputum smear and culture for acid-fast bacilli were performed for all patients 3 times. Sputum polymerase chain reaction was also performed for all patients. Mycobacterial identification was performed via polymerase chain reaction and routine identification tests for all culture-positive cases. RESULTS: Of the 105 patients in the study, 12 (11.43%) were identified to have NTM infection. The identified mycobacteria were classified in order of prevalence as Chelonae (8 cases), Simiae (2 cases), Aloei (1 case), and Farcinogen (1 case). Based on radiologic findings, most of the cases demonstrated bilateral nodularity (83.3%) and also multifocal bronchiectasis (75%). Notably, cavitary lesions were present in 41.7% of the cases. CONCLUSION: Based on the findings of this study, it is essential that such cases be identified before commencing MDR-TB treatment.