Host susceptibility spectrum and diagnostic challenges in pediatric nontuberculous mycobacterial disease: a case series of five patients with literature review.

Objective: Pediatric nontuberculous mycobacterial (NTM) infections are frequently misdiagnosed due to their heterogeneous clinical presentations, which can mimic pulmonary tuberculosis, common respiratory diseases, or other infectious conditions depending on the site of involvement. This case series aimed to characterize the host susceptibility spectrum underlying pediatric NTM infection across both pulmonary and extrapulmonary sites, with emphasis on the diagnostic role of targeted next-generation sequencing (tNGS). Methods: We conducted a retrospective analysis of five pediatric patients with confirmed NTM infection diagnosed at Fujian Provincial Fuzhou Pulmonary Hospital between January and December 2025. Clinical characteristics, predisposing factors, therapeutic regimens, and clinical outcomes were systematically reviewed and discussed in the context of relevant literature. Results: The cohort included 5 children aged 7 months to 12 years. Pathogenic species were Conclusions: Pediatric NTM infection is associated with a broad spectrum of predisposing factors, including bronchiectasis, cystic fibrosis, congenital airway anomalies, and systemic immunodeficiency such as DiGeorge syndrome. tNGS demonstrated significant diagnostic value in identifying NTM species and should be considered when conventional methods are insufficient.