Nontuberculosis mycobacteria at a multiresistant tuberculosis reference center in Bahia: clinical epidemiological aspects.

Objective: Examine the prevalence and clinical/epidemiological aspects of patients with nontuberculous mycobacteria (NTM) isolated from sputum provided by an outpatient clinic specializing in the treatment of multiresistant tuberculosis (MRTB) in Bahia, Brazil.

Methods: All patients followed at the MRTB outpatient clinic of the Octávio Mangabeira Specialized Hospital (HEOM) were evaluated retrospectively from July 1998 to July 2003. All patients underwent direct examinations and cultures to identify the mycobacteria species found during initial and subsequent evaluations. The following variables were recorded: age, gender, clinical symptoms and signs, pre-existing lung disease, prior TB treatment, HIV serology, and NTM species. Categorical and quantitative variables were respectively characterized using proportions and measures +/- SD.

Results: NTM were isolated in 19 of 231 patients (8.2%; 95%CI: 5.2%-12.3%), with the following species distribution: 58% (11/19) M. chelonae/abscessus; 16% (3/19) M. avium-intracellular complex; 16% (3/19) M. kansasii; and 11% (2/19) M. fortuitum. HIV serology was positive for just one patient (5%), from whom M. chelonae/abscessus was isolated. Productive coughing was observed in all cases. American Thoracic Society (ATS) diagnostic criteria for NTM lung disease were observed in 14 patients (74%).

Conclusion: The prevalence of NTM isolated from patients referred to the MRTB outpatient clinic in Bahia was 8.2% (CI 95%: 5.2%-12.3%); rapid-growth mycobacteria (M. chelonae/M. fortuitum) were the most frequently isolated (68%).