Rochester Criteria for Febrile Infants

Rochester Criteria Calculator
Previously healthy (term, no perinatal abx, no prior hospitalization)
No focal bacterial infection (except otitis media)
WBC 5,000-15,000/mm³
Band count ≤1,500/mm³
Urinalysis normal (≤10 WBC/HPF)
Stool WBC ≤5/HPF (if diarrhea)
Classification: Low Risk
Low Risk
All Rochester criteria met. Risk of serious bacterial infection ~1%. Consider outpatient management with close follow-up.
Determines whether febrile infants are low risk for serious bacterial infection.

Why Use

Identifies infants at low risk for serious bacterial infection (SBI), defined as bacteremia, meningitis, osteomyelitis, suppurative arthritis, soft tissue infections (cellulitis, abscess, mastitis, omphalitis), urinary tract infection, gastroenteritis, or pneumonia. Infants ≤60 days may present with minimal signs and symptoms, or appear similarly to those with viral infection. The criteria can help identify SBI; prevalence is 10-12% in this group, with the majority (>90%) representing UTI ( Biondi et al 2013 , Greenhow et al 2014 ) May reduce over-testing and treatment of well-appearing febrile infants.

When to Use

Well-appearing infants ≤60 days old presenting to the emergency department for a chief complaint of fever ≥38ºC (100.4ºF), or found to have fever on presentation for other complaint. Ill-appearing infants should be redirected to sepsis guidelines.

Formula

Selection of the appropriate criteria: Infant appears generally well. No evidence of focal infection (skin, soft tissue, bone, joint, or ear). No prior illness: Born at term (≥37 weeks gestation) No perinatal antibiotics No unexplained hyperbilirubinemia No previous hospitalizations No chronic or underlying illness Not hospitalized longer than mother after delivery Lab values WBC 5,000-15,000/mm³ (5 to 15 × 10⁹/L) Band neutrophils ≤1,500/mm³ (≤1.5 × 10⁹/L) No diarrhea; or, if diarrhea present, fecal leukocytes <5 WBC/hpf Urine WBC <10/hpf If all of the above are true, the infant is low risk for SBI.

Pearls / Pitfalls

While the validation study looked at infants any age ≤60 days, in clinical practice infants <28 days are often considered NOT low risk due to age. Premature infants should be assessed based on corrected age (e.g. for infant born at 30 weeks gestational age, subtract 7 weeks from chronologic age).

Management

If LOW risk (in the derivation study, SBI occurred in 1% of low risk infants): Limited testing, including complete blood count, blood culture, urinalysis, and urine culture, is recommended. These infants generally do not require antibiotics. Generally safe to be discharged home, given no social concerns or question of ability to follow up with their primary care provider (PCP). If NOT low risk (in the study, SBI occurred in 12.3% of infants not at low risk): Further testing is required, including complete blood count, blood culture, urinalysis, urine culture, and cerebrospinal fluid (CSF) testing. Empiric broad spectrum antibiotic coverage is indicated. Admission is recommended, pending negative cultures at 24-36 hours.

Advice

Herpes simplex virus (HSV) risk factors should be carefully assessed, including: maternal history of HSV infection or primary lesions at delivery, household contacts with lesions, vesicular rash, presentation with seizures, or pleocytosis on cerebrospinal fluid (CSF) testing. Positive viral testing (e.g. RSV, influenza) reduces serious bacterial infection (SBI) likelihood by ~50%, but the risk of concurrent SBI is NOT zero ( Greenhow 2014 , Krief 2009 ). The gold standard for urine culture is a sample obtained via straight catheterization. “Bag” urine introduces risk of specimen contamination with skin flora. Obtain blood, urine, and CSF samples BEFORE starting antibiotics, if possible. Differential diagnosis of ill-appearing infants <60 days of age should also include the following: congenital heart disease, metabolic disease (e.g. galactosemia), congenital adrenal hyperplasia with adrenal crisis, and non-accidental trauma.

More Information

Interpretation: Criteria Risk for SBI Recommendation 12 Low risk (<1%) Obtain limited tests: CBC, blood culture, urinalysis, and urine culture. Antibiotics not necessary. Consider discharge with close PCP follow-up. <12 Not low risk Obtain CBC, blood culture, urinalysis, urine culture, and CSF. Empiric antibiotics indicated. Admit pending negative cultures at 24-36 hrs and continued well-appearance.

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