Late-Onset Sepsis in Very Low Birth Weight Infants

Abstract

BACKGROUND AND OBJECTIVES Late–onset sepsis is associated with significant morbidity and mortality among very low birth weight (VLBW) infants. Our objective was to determine risk factors associated with late-onset sepsis and to present temporal trends in overall and pathogen-specific rates. METHODS Population-based study by the Israel Neonatal Network on VLBW infants (≤1500 g) born between 1995 and 2019. Late-onset sepsis required clinical symptoms and microbiologic confirmation. Bivariate and multivariable analyses were performed to identify risk factors. The study period was divided into 4 epochs. Overall and pathogen-specific late-onset sepsis rates for each epoch were compared. RESULTS The study population comprised 31 612 VLBW infants, of whom 7423 (23.5%) had late-onset sepsis. An increased adjusted risk of late-onset sepsis was associated with gestational age <27 w (odds ratio [OR] 8.90, 95% confidence interval [CI] 7.85–10.09) and delivery room resuscitation (OR 1.43, 95% CI 1.34–1.52) and a decreased adjusted risk among infants born between 2013 and 2019 (OR 0.32, 95% CI 0.29–0.35). Late-onset sepsis rates declined from 29.5% in 1995 to 2000 to 13.0% in 2013 to 2019. Gram-negative and fungal rates decreased in all epochs, whereas gram-positive rates decreased only in the last epoch. The adjusted hazard ratios (95% CI) decreased in the 2013 to 2019 versus 1995 to 2000 epochs and were: all late-onset sepsis, 0.40 (0.37–0.43); gram-positive, 0.47 (0.37–0.59); gram- negative, 0.54 (0.48–0.61); fungal, 0.17 (0.12–0.22). CONCLUSIONS The strongest risk factor for late-onset sepsis was gestational age <27 w. Over a 25-year period, the pathogen-specific rates of late-onset sepsis among VLBW infants decreased approximately twofold for gram-positive and gram-negative bacterial infections and sixfold for fungal infections.