Characterization of Bacteremia in Pediatric Oncology Patients
Maria Ines Sormani, Valeria Torre, Sofia Esposto, Alejandra Alancay, Yanina Lagala, Micaela Pichinenda, Anastasia Regalado, Marcio FagnaniAbstract
Introduction
Bacteremia represents one of the major post-chemotherapy complications in oncohematological patients. Implementing appropriate empirical treatment based on local epidemiology is essential to reduce morbidity and mortality associated with these infections.
Materials and Methods
Retrospective, descriptive study. Included bacteremia episodes in patients under 18 years old with hematological-oncological diseases, admitted to a high-complexity pediatric hospital between September 2022 and October 2024. Transplanted patients were excluded.
Objectives
To evaluate clinical findings, laboratory results, microbiological characteristics, resistance patterns, and initial empirical treatment of bacteremia in oncohematological patients.
Results
A total of 123 bacteremia episodes in 67 patients were evaluated. The median age was 103 months, with a predominance of the male sex (51.2%). The most frequent underlying disease was Acute Lymphoblastic Leukemia (ALL) in 82 cases (66.7%). Fifty-eight patients received chemotherapy in the last 10 days, and 90% were exposed to antibiotics in the last 90 days. Eighty-seven episodes (71%) presented neutropenia. Among the clinical findings, 97.5% presented fever, 27 (22%) were primary bacteremias, and in secondary bacteremias, the main associated focus was the central venous catheter in 64 cases (52%) followed by an abdominal focus in 35 (28.5%). Regarding microbiological analysis, the most frequent bacteria were Gram-negative bacilli (GNB) 64% (78/123): enterobacteriaceae 79.5%, non-fermentative GNB 20.5%. The most frequent isolate was Klebsiella pneumoniae (22/78) followed by Escherichia coli (21/78). Gram-positive cocci (GPC) represented 36% (45/123), with 14 Staphylococcus coagulase-negative and 12 Streptococcus viridans as the most frequent isolates. In relation to enterobacteria, resistance mechanisms were detected in 25 episodes (25/62). The most frequent was ESBL 56% followed by MBL + ESBL 28%. The initial empirical treatment (IET) was adequate in 77% of all episodes. Regarding clinical evolution, 37 episodes (30%) had septic shock, 78% GNB and 22% GPC; of these, 6 patients died, of which 4 (67%) presented MBL+ESBL isolates.
Conclusions
Bacteremia occurred mainly in neutropenic oncohematological patients. Enterobacteriaceae were the most frequently detected microorganisms. The ESBL resistance mechanism prevailed, followed by MBL+ESBL. Local epidemiological knowledge is essential for effective IET and antimicrobial resistance control.