INTRODUCTION

The challenge for the emergency physician faced with a febrile child is to identify the patient at high risk for serious underlying infection, while limiting unnecessary testing and treatment. Because immune function, likely pathogens, and exam findings vary significantly from birth to early childhood, the risk of serious bacterial illness in febrile children is usually stratified by age.

EPIDEMIOLOGY

Neonates (birth to 1 month) are at particularly high risk for serious bacterial infection (SBI), including bacteremia, meningitis, pneumonia, urinary tract infections (UTIs), bacterial gastroenteritis, and osteomyelitis (see Chapter 45, Work-Up of Newborn Fever). About 12% of all febrile neonates presenting to a pediatric emergency department (ED) have SBI. The most common types of bacterial infection in this age group are UTIs and bacteremia, and the predominant bacterial pathogen overall is Escherichia coli. Neonates are typically infected by more virulent bacteria (e.g., group B streptococci) than older children. Only a small percentage of neonates are infected with other streptococcal species, such as Streptococcus pneumoniae, and there has been an overall decline in invasive pneumococcal disease since the introduction of the heptavalent pneumococcal conjugate vaccine (PCV7), even in this unvaccinated age group. In addition, neonates are more likely than older children to develop serious sequelae from viral infections (e.g., herpes simplex virus meningitis).