Impact of a PCT(Procalcitonin) Rapid Test -Based Approach on ATB (Antibiotics) Use in Children With Fever Without Source

Inclusion Criteria: * Febrile children aged 6 days to \<36 months old presenting to an ED at their initial visit with an acute illness for a maximum of 8 days and diagnosed with a FWS defined as body temperature (measured at home or the ED) \> 38°C and a physical examination by a physician without source * Oral non-opposition will be requested from one of the parents or caregivers of the patient. * No current antibiotic treatment or within the 48 hours before the ED presentation. * Parental affiliation with an appropriate health insurance system * Parents speaking French Exclusion Criteria: * A clear source of fever identified after a careful inspection of medical history and a physical examination * No fever on consultation or previously subjectively assessed by parents without use of a thermometer * Refusal of the parents to participate * Child ≥ 36 months or \< 6 days old (ie, early-onset neonatal infection) * Ongoing ABT treatment or within the 48 hours before ED presentation * Children with FWS who revisited the ED after their initial visit * Participation with another interventional study involving human subjects or being in the exclusion period at the end of a previous study involving human subjects