Authors’ Response

We thank Dr Woods for his thoughtful comment emphasizing the importance of submitting a sufficient quantity of blood for culturing. Blood cultures are recommended for all infants and accurate results are required for further management. Dr Woods raises a good point about the volume required to assess IMs in blood, a particular concern in the youngest infants, 8 to 21 days. In this group, IMs are not needed for initial decision-making because the guideline recommends all 8- to 21-day-old infants have CSF evaluated, antimicrobial agents administered, and close observation in hospitals with staff experienced in the care of young infants. Accordingly, the key action statement intentionally does not state that IMs “should” be obtained in this age group. Some members of the subcommittee find IMs potentially useful later in the course of hospitalization for addressing what may be falsepositive culture results or determining length of stay, so the key action statement allows for this, using the permissive word “may.” For older infants, IMs determine further steps in evaluation and management and are, therefore, useful. It is worth noting that fever is an IM. Therefore, if a temperature is >38.5°C, a decision point indicating an action if any IM is positive does not necessarily require blood results. For infants with lower temperature elevations, blood IMs are recommended for decision-making.

None of the recent published clinical decision models,1,2 derived prediction rules,3,4 or prospective observational studies4 have been able to identify all infants with IBIs. The use of empirical antimicrobial agents, along with close and active monitoring, has prevented negative outcomes in many infants who otherwise would have been missed by strictly relying on risk criteria. For the AAP Febrile Infant Clinical Practice Guideline, we anticipate that the extensive data underlying the proposed clinical and laboratory markers,5 along with adequate blood cultures, will allow clinicians to “safely do less.”6