Febrile Infant Risk Stratification

Dr. Francis Villanueva

Serious bacterial infections, such as bacteremia and bacterial meningitis are found in 10% of febrile infants under 60 days of age. Most attendings agree that any infant < 28 days of age presenting with fever, will get a complete sepsis work up, including a lumbar puncture. However, there is no consensus on well appearing febrile infants age 29-60 days old. Physicians face a decision between the risks of a lumbar puncture versus the rarity of bacterial meningitis yet, the neurologic sequalae or even death if treatment is delayed.



Aronson, Paul L, et al. “Risk Stratification of Febrile Infants ≤60 Days Old Without Routine Lumbar Puncture.” Pediatrics, American Academy of Pediatrics, Dec. 2018, https://www.ncbi.nlm.nih.gov/pubmed/30425130?dopt=AbstractPlus.

Study Design

Multi-center case control study of records from 11 children’s hospital across the United States.

Infants less than 60 days old with invasive bacterial infection were identified through each hospital’s EMR.

Documentation and lab results were reviewed and patients were classified as low risk or high risk based on the modified Philadelphia and Rochester Criterion, neither of which require lumbar puncture for risk stratification.


Out of 135 cases of well-appearing previously healthy, febrile infants with invasive bacterial illness, 25 and 11 infants were classified as low risk by the Rochester and modified Philadelphia criteria, respectively.

Of the 17 cases of bacterial meningitis found in the study, none were classified as low risk by the modified Philadelphia criteria.

  • The modified Philadelphia criteria was highly sensitive in the risk stratification of infants with IBI.

  • Classified all infants with bacterial meningitis as high risk without CSF testing

  • Only 1 of 300 febrile infants (0.3%) who do not appear ill will have an IBI, specifically with bacteremia, will be missed with this criteria.

  • The sensitivity of the modified Philadelphia criteria coupled with the rarity of bacterial meningitis makes it a relatively good risk stratification tool.



  • The use of the modified Philadelphia criteria and other risk stratification tools for febrile infants should be site dependent. Know your population, site resources, and ease of follow up for your specific circumstance.

  • Gestalt, experience, and site protocol will often dictate what risk stratification tools are followed.

Baskin MN, Goh XL, Heeney MM, Harper MB. Bacteremia risk and outpatient management of febrile patients with sickle cell disease. Pediatrics. 2013;131(6):1035–1041

Paxton RD, Byington CL. An examination of the unintended consequences of the rule-out sepsis evaluation: a parental perspective. Clin Pediatr (Phila). 2001;40(2):71–77

Smith, Clay. “PECARN - Only 1 in 500 Infants Have Bacterial Meningitis at 29-60 Days.” JournalFeed, JournalFeed, 8 Mar. 2018, https://journalfeed.org/article-a-day/2018/pecarn-only-1-in-500-infants-have-bacterial-meningitis-at-29-60-days.

Smith, Clay. “A Step-by-Step Approach to Infant Fever.” JournalFeed, JournalFeed, 9 Sept. 2016, https://journalfeed.org/article-a-day/2016/a-step-by-step-approach-to-infant-fever.