Diagnosis and evaluation of nontuberculous mycobacterial pulmonary disease

Abstract

Background: Nontuberculous mycobacteria (NTM) represent a broad spectrum of acid-fast bacilli, excluding the pathogens responsible for tuberculosis and leprosy. Over 200 species have been identified and classified as NTM, based on shared phenotypic characteristics. These bacteria are prevalent in diverse environments and are implicated in NTM pulmonary disease (NTM-PD), resulting from interactions between the host, the environment, and the microorganism.Current Concepts: Diagnosing NTM-PD necessitates a comprehensive approach. It is essential to identify the risk factors, including underlying lung conditions, compromised immune responses, and other host-specific factors. The clinical diagnosis considers pulmonary or systemic symptoms aligned with the disease and the exclusion of alternative pulmonary disorders. Radiological evaluations, such as chest X-rays and computed tomography scans reveal patterns indicative of the disease, including fibrocavitary and nodular bronchiectatic forms. Microbiological criteria are fundamental to the diagnostic process and require a minimum of two positive cultures from separate sputum samples or a single positive result from invasive techniques, such as bronchoscopy or biopsies.Discussion and Conclusion: As there are multiple phenotypes of NTM-PD, it is necessary to assess the likelihood of the disease in individuals with increased risk factors. A combination of the clinical, radiological, and microbiological criteria is essential for the accurate diagnosis of NTM-PD. Once diagnosed, a thorough assessment is necessary to guide appropriate management decisions.