Abstract Background Moraxella species are commensal organisms of the upper respiratory tract that only occasionally cause invasive infection. Pediatric Moraxella bacteremia is extremely rare, and its clinical features and optimal management remain poorly defined. Methods We conducted a single‐center, retrospective observational study at Tokyo Metropolitan Children's Medical Center. Patients with blood cultures yielding Moraxella spp. between April 2010 and March 2024 were identified. Clinical and microbiological data were extracted from electronic medical records. The primary outcome was all‐cause 28‐day mortality. Results Among 24 patients (28 episodes) with blood cultures positive for M. catarrhalis or M. osloensis , 13 episodes were excluded as contamination. Eleven patients (15 episodes) with confirmed bacteremia were analyzed: 8 episodes were due to M. osloensis and 7 to M. catarrhalis . Two patients had recurrent episodes (one patient with congenital nephrotic syndrome had four episodes of M. catarrhalis bacteremia). Overall, 10 of 11 patients (91%) had underlying immunodeficiency. Central venous catheters were present in 6 of 8 M. osloensis episodes, which were classified as catheter‐associated bacteremia. In the M. catarrhalis group, pneumonia was the most likely focus in 2 of 7 episodes. Antimicrobial therapy commonly included cefepime or ampicillin‐sulbactam for M. osloensis and cefotaxime or ampicillin‐sulbactam for M. catarrhalis . The median duration of antimicrobial therapy was 14 days in both groups. No patients required pediatric intensive care unit (PICU) care and no 28‐day mortality occurred. Conclusion The patients with bacteremia due to M. osloensis or M. catarrhalis had favorable clinical outcomes.
Shin et al. (Thu,) studied this question.