The End of Routine Lumbar Punctures for the Febrile Infant 28 Days and Younger?

For decades, the teaching in pediatric emergency medicine has been consistent: “Young febrile infants (0-28 days) with fevers get a full sepsis workup.” This traditionally means blood, urine, and cerebrospinal fluid (CSF) cultures, followed by admission and antibiotics. The fear of missing bacterial meningitis—a devastating infection—has driven this aggressive approach. But is a lumbar puncture (LP) truly necessary for every well-appearing febrile infants in the first month of life? A new international study, “Prediction of Bacteremia and Bacterial Meningitis Among Febrile Infants Aged 28 Days or Younger,” published in JAMA, investigates if the PECARN febrile infant prediction rule can identify which of these young infants might safely forego an LP [1, 2].

Study Design

  • Study Question: Can the updated PECARN prediction rule accurately identify febrile infants ≤28 days old at low risk for invasive bacterial infections (bacteremia and/or bacterial meningitis)?
  • Type of Study: Pooled analysis of 4 prospective cohort studies (plus a secondary analysis including 2 US-based PECARN cohorts).
  • Setting: Pediatric emergency departments across 6 countries (Canada, Spain, Switzerland, Italy, UK/Ireland) during 2008-2024
  • Inclusion Criteria: Non-ill-appearing, full term (≥37 weeks) infants aged 0–28 days with fever (≥38.0°C), who underwent blood and urine testing including procalcitonin (PCT).
  • Exclusion Criteria: Critically ill appearance, prematurity, comorbidities, or antibiotic use in preceding days.
  • Outcome Measured: Diagnostic accuracy for invasive bacterial infections (IBI): bacteremia or bacterial meningitis

Methods

The authors applied the updated PECARN prediction rule to this neonatal population. The Rule Criteria for “Low Risk”:

  1. Urinalysis: Negative
  2. Absolute Neutrophil Count (ANC): ≤ 4,000/mm³
  3. Serum Procalcitonin (PCT): ≤ 0.5 ng/mL

If an infant met ALL three criteria, they were classified as “Low Risk.”

Results

Prevalence of Invasive Bacterial Infections (IBIs) among all studied infants:

  • 4.5% overall had IBIs.
  • 3.8% had bacteremia.
  • 0.7% had bacterial meningitis.

Performance of the PECARN Rule in Young Febrile Infants (0-28 days):

  • 41.1% of infants were identified as low risk.
  • Sensitivity: 94.2% (95% CI: 85.6% – 97.8%)
  • Negative Predictive Value (NPV): 99.4% (95% CI: 98.1% – 99.8%)
  • Specificity: 41.6% (Low specificity means many infants without infection still screen as “high risk”).

Crucial Safety Findings:

  • Missed Bacterial Meningitis: ZERO. There were 0 missed cases of bacterial meningitis among the low-risk infants in both the primary and secondary analyses (0 out of 33 meningitis cases total).
  • Missed Bacteremia: The rule missed 5 cases of bacteremia. However, the editorial notes all missed cases occurred in infants aged 8–21 days.

Authors’ Insight

The authors emphasize that while specificity is lower (leading to some “unnecessary” workups), the sensitivity for the most dangerous outcome—bacterial meningitis—was perfect in this dataset.

“No infants classified as being at low risk had bacterial meningitis… These results may support shared decision-making regarding select vs routine use of lumbar puncture.”

Clinical Implications

This study challenges the dogma that all febrile infants in the first month of life require an LP.

  • Potential Practice Change: For Non-ill-appearing infants 22–28 days old, these data strongly support using the PECARN rule (normal UA + ANC + procalcitonin) to risk-stratify and potentially avoid LP if low risk.
  • Caution Zone (8–21 days): The accompanying editorial highlights that all “missed” IBI cases were in the 8-21 day age group. Clinicians should thus exercise more caution in this age group. A reasonable approach for a non-ill-appearing infant with normal inflammatory markers and urinalysis might be to skip the LP, give no antibiotics, but still hospitalize for observation. .
  • Requirement: This strategy requires rapid access to procalcitonin. CRP was not evaluated as a substitute in this specific rule analysis.

Caution

While 0 cases of bacterial meningitis were missed, the rule did miss a small number of bacteremia cases (approx. 0.6% risk in the low-risk group). Thus low-risk infants still require blood cultures, observation, and close follow-up.

Take Home Message

For non-ill-appearing febrile infants aged 0-28 days, the PECARN prediction rule (negative UA, ANC ≤ 4000, procalcitonin ≤ 0.5) identified a low-risk group where the risk of bacterial meningitis was zero. This offers an evidence-based approach to potentially spare more than 40% of febrile infants in the first month of life from lumbar punctures.

Why is this important for patients and caregivers

  • Less Trauma: Lumbar punctures (spinal taps) are painful, stressful for parents, and technically difficult in tiny babies. Avoiding them when safe is a huge priority for families.
  • Safety First: The study showed that even if we skip the spinal tap in “low risk” babies identified by blood and urine tests, we are extremely unlikely to miss a dangerous brain infection (bacterial meningitis).
  • Reduced Hospitalization: Identifying low-risk infants ≤28 days old is the first step toward shorter hospital stays or potentially managing select cases at home in the future.
  • Reduced Antibiotic Exposure: Low-risk infants ≤28 days old may safely avoid routine antibiotics, sparing them from potential side effects and helping to preserve their developing microbiome.

References

  1. Burstein B, Waterfield T, Umana E, Xie J, Kuppermann N. Prediction of Bacteremia and Bacterial Meningitis Among Febrile Infants Aged 28 Days or Younger. JAMA. Published online December 8, 2025. doi:10.1001/jama.2025.21454
  2. Searns JB, O’Leary ST. Moving the Field Forward to Safely Do Less With Febrile Neonates. JAMA. Published online December 8, 2025. doi:10.1001/jama.2025.23133
  3. Pantell RH, Roberts KB, Adams WG, et al; Subcommittee on Febrile Infants. Evaluation and management of well-appearing febrile infants 8 to 60 days old. Pediatrics. 2021;148(2):e2021052228. PMID 34281996
  4. Kuppermann N, Dayan PS, Levine DA, et al; Febrile Infant Working Group of the Pediatric Emergency Care Applied Research Network (PECARN). A clinical prediction rule to identify febrile infants 60 days and younger at low risk for serious bacterial infections. JAMA Pediatr. 2019;173(4):342-351. doi:10.1001/jamapediatrics.2018.5501. PMID 30776077

Michelle Lin, MD

Michelle Lin, MD

University of California, San Francisco

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