Respiratory infections due to nontuberculous mycobacterias.

The most common infections caused by nontuberculous mycobacteria (NTM) are lung infections. The microorganisms causing these infections most frequently are Mycobacterium avium complex, Mycobacterium kansasii and Mycobacterium abscessus complex. Their incidence has increased in the last three decades. After identifying an NTM in the respiratory tract, clinical and radiological aspects must be considered to determine if isolations are clinically relevant. Predisposing conditions that could contribute to infection must also be investigated. Pulmonary disease due to NTM is presented in three clinical forms: a) pneumonitis due to hypersensitivity; b) fibrocavitary form; and c) nodular-bronchiectasic. The diagnosis of respiratory disease due to NTM does not make it obligatory to immediately initiate treatment. Before initiating the latter, other factors must be considered, such as age, comorbidities, life expectancy, due to the prolonged nature of treatments, with potential side effects and, in many cases, only a slight response to the treatment.