Infecções associadas à assistência à saúde em unidades de terapia intensiva neonatal: uma década de vigilância epidemiológica

Abstract

Introduction: Healthcare-associated infections (HAIs) represent a major challenge in Neonatal Intensive Care Units (NICUs), particularly among premature and low birth weight neonates, whose immunological immaturity and frequent exposure to invasive procedures increase susceptibility to infection. The epidemiology of neonatal HAIs is influenced by socioeconomic and regional factors, as well as local microbiological profiles and antimicrobial resistance patterns. Despite their substantial impact on morbidity, mortality, and healthcare costs, long-term surveillance studies describing the behavior of neonatal HAIs are still scarce. Objective: To describe the epidemiology of HAIs in a NICU over a ten-year period, to evaluate the factors associated with infection and mortality, and to characterize the causative microorganisms and their antimicrobial resistance patterns. Methods: A retrospective cohort study was conducted including newborns hospitalized in the NICU of a tertiary university hospital between 2015 and 2024. Demographic data were collected, and incidence indicators and risk factors for infection and death were calculated. Results: During the study period, the incidence density of HAIs was 50/1000 patient-days (22.3%), varying from 14 in 2015 to 19/1000 patient-days in 2024. Bloodstream infection was the predominant site, followed by eye infection. The lethality rate was 16%, with the highest rate in 2016 (70.8%) and the lowest in 2020 (7.4%). Low birth weight, prematurity, prolonged hospital stays, use of invasive devices, and fungal infections were independently associated with a higher risk of adverse outcomes, including mortality. The main microorganisms were Staphylococcus epidermidis (28.5%), Klebsiella pneumoniae (11.1%), and Staphylococcus aureus (9.0%). The number of multidrug-resistant microorganisms was 30/1000 patient-days, varying from 7 in 2015 to 11/1000 patient-days in 2024. Conclusion: This long-term surveillance study highlights the high incidence HAIs, as well as the predominance of Gram-positive bacteria, variation in antimicrobial resistance over the years, and risk factors for infection and mortality linked to patient severity. Continuous epidemiological surveillance and targeted infection prevention strategies are essential to improve clinical outcomes and guide evidence-based interventions in NICUs.