The Epidemiology of Nontuberculous Mycobacteria in Cystic Fibrosis

Background: Nontuberculous mycobacteria (NTM) are opportunistic pathogens responsible for chronic pulmonary infections, primarily affecting individuals with underlying conditions such as cystic fibrosis (CF). The aim of this review is to present the epidemiological profile of NTM in CF patients, with a focus on incidence, prevalence, predominant species, and geographic distribution. Methods: The search included cross-sectional, retrospective, and prospective observational studies published in English that reported epidemiological data concerning the isolation and/or infection of individuals with CF by NTM. NTM infection was defined as the isolation of any NTM species at least once per patient. Out of an initial 1120 references identified in PubMed, and following the application of exclusion criteria based on PRISMA guidelines, a total of 78 studies were included. Results: The reported prevalence of NTM in CF patients ranges globally from 0% to 40.9%. This wide variability is attributed to population heterogeneity, study period, and geographical region. Of the studies included, 30 were conducted in Europe and 25 in the U.S.A. Mycobacterium abscessus and the Mycobacterium avium complex (MAC) were the most commonly isolated species, with MAC being more prevalent in older individuals. The incidence of NTM pulmonary disease was high, with the majority of cases being associated with M. abscessus. Although emerging evidence suggests that CFTR modulator therapy may reduce the risk of NTM isolation and/or disease, current data remain limited. Conclusions: Nontuberculous mycobacteria are significant pathogens in patients with cystic fibrosis, with a negative impact on respiratory health.