Legionella bozemanii lymphadenitis in an immunocompetent child and the role of sequencing in the diagnostic evaluation of culture-negative pediatric lymphadenitis: a case report

Background Legionella species comprise a group of fastidious, intracellular, Gram-negative pathogens which are most associated with pulmonary disease, though extrapulmonary manifestations have been described. Some species, such as Legionella bozemanii , are thought to primarily affect immunocompromised hosts; however, prevalence may be underappreciated due to challenges in traditional culture-based detection methods. Case Summary This case report describes a 3-year-old healthy male who experienced subacute cervical lymphadenitis refractory to medical and surgical management. After initial debridement, he had no growth on aerobic, anaerobic, acid-fast bacilli, or fungal cultures, at which time 16s rRNA sequencing was sent from lymph node aspirate. Following discharge testing resulted positive for L. bozemanii, and he responded well to 1 month of oral azithromycin therapy. Conclusion To our knowledge, this is the first documented pediatric case of L. bozemanii both as a cause of cervical lymphadenitis and as a pathogen in an immunocompetent child. This case highlights the usefulness of molecular diagnostic methods in cases of refractory, culture-negative pediatric lymphadenitis and encourages increased diagnostic suspicion of Legionella species as causative agents of this disease.