Retrospective pediatric NTM study finds cervical lymphadenitis predominant, diagnostic delays common

Nontuberculous mycobacteria (NTM) are rare but emerging pathogens in pediatric populations, particularly in countries where BCG vaccination has been discontinued. Their diagnosis is often delayed due to nonspecific symptoms and limited microbiological sensitivity. We conducted a retrospective cohort study of all pediatric patients with confirmed or clinically probable NTM disease, diagnosed at the National Institute for Pediatric Tuberculosis and Respiratory Diseases in Slovakia between 2017 and 2024. Medical records from 2012 to 2016 were screened, but no cases fulfilling inclusion criteria were identified. Clinical characteristics, diagnostic approaches, therapeutic strategies, and patient outcomes were systematically evaluated. In total, 30 patients were diagnosed. The majority of cases (27/30) involved cervical lymphadenitis (including two with concurrent pulmonary involvement), most commonly affecting children between 1 and 2 years. In addition, one patient was diagnosed with a pulmonary form of NTM disease, one with NTM-associated osteomyelitis, and one with a skin and soft tissue infection. Mycobacterium avium complex was the most frequently identified species, detected in 8 patients. Bacteriological confirmation was achieved in 53.3% of cases, while histological evidence of granulomatous inflammation was found in 86.7%. The median time to diagnosis was 45 days (IQR: 31–109.5), with longer delays in culture-negative patients (p = 0.0648). Surgical excision was performed in 25 of 27 patients with lymphadenitis, 60% received adjunctive antibiotic therapy. Follow-up data were available for 19 patients: 15 had full recovery, 3 experienced recurrent upper respiratory tract infections, and 1 immunocompromised patient died from miliary tuberculosis. This is the first national study on pediatric NTM disease in a post-BCG vaccination era in Slovakia. Despite centralization of care, diagnostic delays were common, particularly in bacteriologically negative cases. These findings underscore the need for early tissue sampling, comprehensive microbiological evaluation, and interdisciplinary collaboration to improve diagnostic efficiency.