A Retrospective Review Of Serious Infections In Febrile Infants 0-90 Days Old

Background: Fever without source in infants is a common clinical problem that accounts for many ambulatory care visits and hospitalisations. Currently, there is no reliable method of identifying those at risk of serious infection (SI). Objective: The goal of this study was to determine the incidence and identify the predictors of SI in febrile infants who presented to the emergency department (ED). Methods: This was a single-centre retrospective cohort study of children presenting to a Singapore tertiary hospital paediatric unit between 1 July 2018 and 31 December 2018. Children were included if they were aged 0-90 days and presented to the ED with a fever. SI was defined as urinary tract infection (UTI), sepsis, bacteraemia, meningitis (viral and bacterial), enterocolitis, osteomyelitis, abscess or pneumonia. Results: Of the 659 infants, 161 (24.4%) were diagnosed with SI. Meningitis (49.7%) was the most common SI, followed by UTI (45.3%), enterocolitis (5.6%), sepsis (3.1%) and bacteraemia (2.5%). Factors significantly associated with SI were aged 29-60 days, male sex, Severity Index Score (SIS) <10, absolute neutrophil counts >10x10(9)/L, C-reactive protein (CRP) >20 mg/L and procalcitonin >0.5 ng/mL. Multivariate analysis entering all these items retained only male sex, SIS 20. Conclusion: Among hospitalised infants aged 0-90 days, the incidence of SI was 24.4%, and invasive bacterial infection was 0.6%. Meningitis was the most common SI followed by UTI. SIS and CRP can be used to predict SI in infants <90 days old.