The Step-by-Step approach can be used to triage a young (<= 90 day old) febrile infant. The authors are from multiple institutions in Europe.

Patient inclusion: febrile (temperature >= 38°C) infant <= 90 days old without source of infection


Exclusions: clear source of fever identified, no fever in ED, no objective evidence of fever at home


Outcome: invasive bacterial infection


High risk patient:

(1) abnormal pediatric assessment triangle (ill-appearing)

(2) age <= 21 days

(3) leukocyturia

(4) procalcitonin >= 0.5 ng/mL


Intermediate risk patient:

(1) CRP > 20 mg/L

(2) absolute neutrophil count > 10,000 per µL


Low risk patient: everyone else


Performance for identifying an invasive bacterial infection:

• In the study by Gomez et al the e sensitivity is 92% and specificity is 47%, with a claimed negative predictive value of 99%.

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