Related Experiment Video
Updated: May 8, 2026

How to Administer Near-Infrared Spectroscopy in Critically ill Neonates, Infants, and Children
Published on: August 19, 2020
Evaluation of the febrile young infant: an update
1Department of Pediatrics, Section of Emergency Medicine, Yale School of Medicine, New Haven, CT, USA.
Insights
Feverish infants require a sepsis workup to detect serious bacterial infections like meningitis and bacteremia, preventing severe complications. This evaluation is crucial even in well-appearing infants to ensure timely diagnosis and treatment.
Area of Science:
- Pediatrics
- Infectious Diseases
- Emergency Medicine
Background:
- Febrile young infants present frequently in emergency departments.
- Serious bacterial infections (SBIs) occur in up to 15% of these infants.
- Undiagnosed SBIs can lead to severe outcomes like sepsis, death, or neurological damage.
Purpose of the Study:
- To review the evidence guiding the evaluation of febrile young infants.
- To address parental and clinician concerns regarding the necessity of a full sepsis workup.
- To discuss recent findings on SBIs in infants with bronchiolitis and the role of viral testing.
Main Methods:
- Review of existing literature and studies on febrile infants.
- Analysis of the incidence and risks of serious bacterial infections.
- Discussion of diagnostic approaches, including sepsis workup and viral testing.
Main Results:
- A full sepsis workup is recommended to rule out invasive bacterial diseases.
- Early detection of infections like meningitis, bacteremia, and UTI is critical.
- Recent studies highlight the importance of considering viral infections and their impact.
Conclusions:
- The evaluation of febrile young infants necessitates a comprehensive approach to rule out SBIs.
- Understanding the evidence supports the current diagnostic strategies in emergency settings.
- Further research is ongoing regarding viral infections and their role in febrile infants.
Abstract:
The febrile young infant is commonly encountered in the emergency department, and the incidence of serious bacterial infection in these patients is as high as 15%. Undiagnosed bacterial infections such as meningitis and bacteremia can lead to overwhelming sepsis and death or neurologic sequelae. Undetected urinary tract infection can lead to pyelonephritis and renal scarring. These outcomes necessitate the evaluation for a bacterial source of fever; therefore, performance of a full sepsis workup is recommended to rule out bacteremia, urinary tract infection, and bacterial meningitis in addition to other invasive bacterial diseases including pneumonia, bacterial enteritis, cellulitis, and osteomyelitis. Parents and emergency clinicians often question the necessity of this approach in the well-appearing febrile young infant, and it is important to understand and communicate the evidence that guides the approach to these patients. Recent studies examining the risk of serious bacterial infection in young infants with bronchiolitis and the role of viral testing in the febrile young infant will also be discussed in this review.
Related Concept Videos
Methods of reducing fever
Pharmacological Methods of Reducing Fever:
Increased Body Temperature
Drug Dosing: Infants and Children
Patterns of Fever
Types of Fever
Here are the different types of fever:
Pneumonia III: Complications and Assessment

