Pulmonary Mycobacteriosis—The Diagnostic Challenge. The Authors’ Experience

The diagnosis of NTM-related pulmonary disease is based on clinical symptoms, radiological features and several positive cultures of one and the same NTM species from samples obtained from the respiratory tract. Short hospitalization usually does not enable sufficient diagnostic procedures to meet the diagnostic criteria, andthis may lead to the reduction of diagnostic sensitivity. The aim of the study was to draw attention to NTM-related pulmonary disease, to share the authors' experience in the diagnosing of pulmonary mycobacteriosis and to indicate the possibilities of improving the diagnostic accuracy in this disease. A group of 31 patients with sputum, bronchial washing and/or bronchoalveolar lavage fluid (BALF) NTM-positive cultures was selected from a cohort of 245 patients evaluated for tuberculous and nontuberculous mycobacterial diseases (total number of 1277 specimens were invastigated). In two of them NTM related pulmonary disease was diagnosed (caused by M. kansasii and M. avium) at the course of initial evaluation. In the remaining 29 patients the microbiological data did not allow to establish the diagnosis of mycobacterial lung disease mainly due to a small number of samples from the respiratory tract. From this group 13 patients were reevaluated within 3-6 months from the initial investigation. This allowed to identify two new cases of mycobacteriosis (M. kansasii and M. avium). Thus among 31 patients with NTM positive cultures from respiratory tract specimens 4 patients (4/31, 12.9%) met the diagnostic criteria for mycobacterial disaease. Conclusion: Microbiological analysis of an adequate number of samples in symptomatic patients with radiological features suggestive for NTM-related pulmonary disease increses the diagnostic sensitivity in pulmonary mycobacteriosis. Identification of the species in positive cultures is of great importance.