Febrile neutropenia in pediatric acquired aplastic anemia: a 20-year analysis of infections and mortality.

Acquired aplastic anemia (AA) is a life-threatening bone marrow failure disorder, and febrile neutropenia (FN) episodes in children with AA pose significant risks due to infections. The study aimed to investigate the incidence, types, and outcomes of infections during FN episodes in pediatric AA patients. This single-centre retrospective cohort study included 39 pediatric patients with AA diagnosed between January 2004 and January 2024. Data from medical records, including clinical characteristics, laboratory findings, immunosuppressive therapy details, microbiological results, and infection outcomes, were analyzed. Infection sources, pathogens, and outcomes were assessed, and statistical analysis was performed to identify risk factors for infections and mortality. Twenty-five patients were male (64.1%), with a median age of 12,05 years (interquartile range : 6 to 14,94y). A total of 152 FN episodes were evaluated, with 87.1% of patients experiencing at least one episode [median, 4.15 (range:1-15)]. 58 (38.1%) episodes were classified as microbiologically documented infections(MDI); bloodstream infections(BSIs) (n = 36, 23.6%) were the most common, including central line-associated BSIs (CLABSIs) (n = 29, 19%). Among BSIs, 81% (29/36) were caused by Gram-negative (GN) bacteria and 19% (7/36) by Gram-positive (GP) bacteria. The most frequently isolated microorganism was coagulase-negative Staphylococci (n = 13, 8.55%), followed by Escherichia coli (n = 12, 7.89%) with a high extended-spectrum beta-lactamase (ESBL) positivity rate (69%). Fungal infections (proven+probable) were identified in 8 episodes (5.26%), and viral infections in 3 episodes (1.97%). Rabbit-derived antithymocyte globulin (RD-ATG ) was found to be significantly associated with BSIs in both univariable and logistic regression analyses (OR 8.8, 95% CI 1.692-45.761, p = 0.006). The attributable mortality (AM) of infection episodes was 5.2%. In multivariate analysis, bacterial BSIs, particularly GN- BSIs and those receiving RD-ATG, were significant predictors of increased mortality (p < 0.05). GN bacterial infections and fungal infections negatively affected survival. RD-ATG therapy was identified as a risk factor for increased infection frequency and severity, particularly in cases of BSIs and GN bacteremia. Timely and appropriate antimicrobial treatment is crucial, and the high mortality rates associated with severe infections underscore the importance of early detection and intervention.