Delayed presentation is associated with serious bacterial infections among febrile infants: A prospective cohort study.

Introduction: Febrile young infants are at risk of serious bacterial infections (SBIs), which are potentially life-threatening. This study aims to investigate the association between delayed presentation and the risk of SBIs among febrile infants.

Method: We performed a prospective cohort study on febrile infants ≤90 days old presenting to a Singapore paediatric emergency department (ED) between November 2017 and July 2022. We defined delayed presentation as presentation to the ED >24 hours from fever onset. We compared the proportion of SBIs in infants who had delayed presentation compared to those without, and their clinical outcomes. We also performed a multivariable logistic regression to study if delayed presentation was independently associated with the presence of SBIs.

Results: Among 1911 febrile infants analysed, 198 infants (10%) had delayed presentation. Febrile infants with delayed presentation were more likely to have SBIs (28.8% versus [vs] 16.3%, P<0.001). A higher proportion of infants with delayed presentation required intravenous antibiotics (64.1% vs 51.9%, P=0.001). After adjusting for age, sex and severity index score, delayed presentation was independently associated with the presence of SBI (adjusted odds ratio [AOR] 1.78, 95% confidence interval 1.26-2.52, P<0.001).

Conclusion: Febrile infants with delayed presentation are at higher risk of SBI. Frontline clinicians should take this into account when assessing febrile infants.