A nine-year surveillance of healthcare-associated infections in a pediatric Intensive Care Unit: epidemiology, pathogens, and antimicrobial resistance trends.

INTRODUCTION: Healthcare-associated infections (HAIs) remain a major cause of morbidity and mortality in pediatric intensive care units (PICUs), particularly in the context of increasing antimicrobial resistance. This study aimed to evaluate the incidence of HAIs, causative microorganisms, antimicrobial resistance patterns, and temporal trends over a nine-year period in the PICU of a tertiary care hospital. METHODOLOGY: HAI data obtained through active surveillance between January 1, 2016, and December 31, 2024, were retrospectively analyzed. Patients who developed HAIs during their PICU stay were included. Diagnoses were established according to the National Healthcare-Associated Infections Surveillance Network (UHESA) criteria adapted from CDC definitions. Microorganisms were identified using the automated VITEK® 2 system (bioMérieux), and antimicrobial susceptibility testing was interpreted according to EUCAST criteria. Data were evaluated by calendar year and in three-year intervals. RESULTS: No statistically significant change in HAI incidence was observed over the nine-year period (p = 0.56). Gram-negative bacteria were the most frequently isolated pathogens, particularly Klebsiella pneumoniae and Pseudomonas aeruginosa. Among Gram-positive organisms, Staphylococcus aureus and coagulase-negative staphylococci predominated, while Candida species were the most common fungal isolates. The mortality rate among patients with HAIs was 44.7%, markedly higher than the overall PICU mortality rate (1.72%). Resistance rates increased notably, especially for carbapenems and colistin, whereas resistance to linezolid and vancomycin remained limited. CONCLUSIONS: HAIs continue to represent a major clinical challenge in PICUs. Increasing resistance among Gram-negative pathogens highlights the urgent need for strengthened infection control strategies, continuous surveillance, and effective antimicrobial stewardship programs.