Evaluation of the Febrile Infant

Emily M. Herzberg

Lauren Allister

Identification of Infants Unlikely to Have Serious Bacterial Infection Although Hospitalized for Suspected Sepsis

Dagan R, Powell KR, Hall CB, et al. J Pediatr. 1985;107(6):855–860 (Rochester group)

Outpatient Treatment of Febrile Infants 28 to 89 Days of Age With Intramuscular Administration of Ceftriaxone

Baskin MN, O’Rourke EJ, Fleisher GR. J Pediatr. 1992;120(1):22–27 (Boston group)

Outpatient Management Without Antibiotics of Fever in Selected Infants

Baker MD, Bell LM, Avner JR. N Engl J Med. 1993;329(20):1437–1441 (Philadelphia group)

Background

The evaluation and management of the febrile infant <3 months of age has been debated for decades. The prevalence of serious bacterial infection (SBI) in infants 0 to 3 months with fever is approximately 8%, with the highest prevalence (25%) in infants <2 weeks.¹ Determining which febrile infants have an underlying SBI cannot be ascertained solely based on clinical appearance, often necessitating invasive diagnostic testing. Prior to these studies, common practice had been to hospitalize infants <3 months of age for evaluation, antibiotic administration, and observation, which was costly, time consuming, and resource heavy. These landmark investigations were the first to suggest possible pathways for risk stratification of young febrile infants.

Landmark Studies in the Evaluation of the Febrile Infant Rochester Group Objectives

To determine whether results of physical examination, WBC/band count, and UA could predict and stratify risk for SBI.

Methods

Single center, prospective, cohort study in an ED from 1982 to 1984.

Patients

233 previously healthy infants age <89 d hospitalized for sepsis evaluation, stratified to low- and high-risk groups. Infants classified as low risk:

No obvious source of infection
Peripheral WBC count 5,000–15,000/mm³
<1,500 bands/mm³
UA <10 WBCs/hpf
No recent antibiotic therapy

CXR and CSF results were not used for risk stratification.

Intervention

Performance of CBC/differential, UA, LP; blood, urine, and CSF cultures. Viral/stool swabs and CXR obtained dependent on season and symptoms. All were hospitalized and 200 received parenteral antibiotics.

Outcomes

Incidence of SBI among low-risk compared to high-risk infants, and clinical and laboratory findings predictive of SBI.

Key Results