Descriptive analysis of frequency and antimicrobial susceptibility of pathogens isolated from acute leukemia patients with febrile neutropenia over a four-year period at a tertiary hospital

Background: Febrile neutropenia (FN) is a medical emergency in patients with acute leukemia (AL), which increases the risk of life-threatening infections. Emerging antimicrobial resistance (AMR) further complicates management. The study aims to identify pathogen frequency and antimicrobial susceptibility patterns. Methods: A retrospective descriptive study was conducted at a tertiary care hospital from January 2020 to December 2023. Data on AL patients with FN were retrieved from the hospital information system using ICD codes. Results: Of 478 FN episodes identified, 217 (45%) were microbiologically documented. The population consisted of 61.7% males, equally divided between adults (mean age, 38 years) and children (mean age, 8.4 years). AML was the predominant leukemia subtype (52.4%). Respiratory infections (40.5%) and gastrointestinal infections (33.6%) were the leading sources, with 21% having an unknown focus. Chest X-ray detected infection signs in 37.3% of episodes. Hospital stays exceeded 10 days in 67% of admissions, with mortality at 16.5%. A total of 335 pathogens were identified from 217 episodes, with 20.7% involving multiple infections and 4.6% polymicrobial. Gram-negative rods (GNRs) predominated (45.6%), followed by gram-positive cocci (GPCs) (30.7%), fungi (12.2%), viruses (7%), parasites (2.3%), and Mycobacterium tuberculosis (1.7%). Blood cultures yielded 71% of isolates. Leading GNRs were Escherichia coli (37.7%), Pseudomonas aeruginosa (14.5%), and Klebsiella species (13.2%). Among GPCs, Coagulase-negative staphylococci (CoNS) (41.1%), Enterococcus spp. (22.5%), and Staphylococcus aureus (18.6%) predominated. Common fungal pathogens included Aspergillus flavus complex (29.2%) and Candida parapsilosis (14.6%). Antimicrobial resistance among Enterobacterales was 77% to ceftriaxone, 63% to piperacillin–tazobactam, and 47% to carbapenems. Among GPCs, 95% of CoNS and 72% of S. aureus were methicillin-resistant; 76% of Enterococcus were vancomycin-resistant. Overall, 64% of isolates were MDR (62% GPCs, 65.6% GNRs). MDR infections had significantly higher mortality than non-MDR infections (14.0% vs. 3.5%, p = 0.012). Meropenem and vancomycin were the most commonly used empiric agents in FN patients, each administered in 70% of the episodes, however 41% of the FN episodes were not adaequately covered by the empirical regimen. Conclusion: FN in AL patients is frequently associated with infections with GNRs, with a high prevalence of MDR organisms contributing to increased mortality. Surveillance of pathogen distribution and resistance patterns is essential to guide empiric therapy and improve outcomes in this high-risk population. Clinical trial number: Not applicable.