Updated PECARN Rule Shows High Sensitivity in Predicting Invasive Bacterial Infections in Young Febrile Infants: JAMA
Canada: A large international study of febrile infants aged 28 days or younger presenting to emergency departments has found that the updated PECARN prediction rule has high sensitivity and clinically acceptable specificity for ruling out invasive bacterial infections or bacterial meningitis.
Published in JAMA, the pooled investigation—led by Brett Burstein from the Montreal Children’s Hospital and McGill University—brings new clarity to a long-standing clinical dilemma. Fever in the first month of life is one of the earliest and often the only signs of severe bacterial illness, including bacteremia and meningitis. Because of this risk, global guidelines have generally recommended routine lumbar punctures for all febrile neonates to rule out meningitis. However, the burden of invasive testing, especially when most infants do not have serious infection, has prompted interest in more selective, evidence-based approaches.
The updated Pediatric Emergency Care Applied Research Network (PECARN) prediction rule is one such tool. It combines three laboratory markers—urinalysis, serum procalcitonin level, and absolute neutrophil count—to identify infants who are at low risk for bacteremia or meningitis without immediately resorting to lumbar puncture. The current study aimed to rigorously evaluate the accuracy of this rule in identifying infants who are unlikely to have invasive bacterial infections.
The analysis pooled data from four prospective cohort studies conducted across pediatric emergency departments in six countries. Eligible infants were full-term, previously healthy, not ill-appearing, and had documented fever of at least 38°C. All underwent urine, blood, and serum testing, and were classified as low risk if they had a negative urinalysis, procalcitonin ≤0.5 ng/mL, and an absolute neutrophil count ≤4000/mm³.
The key findings of the study were as follows:
- Among the 1537 infants evaluated, 4.5% had invasive bacterial infections, including 11 cases of bacterial meningitis.
- A total of 41.1% of infants met the low-risk criteria based on the PECARN rule.
- The prediction rule showed a sensitivity of 94.2% and a negative predictive value of 99.4%, correctly identifying nearly all invasive infections and missing no cases of meningitis.
- The specificity was lower at 41.6%, indicating limited precision in confirming infections.
- The positive predictive value was 6.9%, highlighting the difficulty in distinguishing infants with true invasive disease.
- In the secondary analysis of 2531 infants, 96 had invasive infections, and 22 had meningitis, with no meningitis cases misclassified as low risk.
The authors note that the rule’s strong sensitivity and excellent ability to rule out meningitis could support shared decision-making between clinicians and parents, especially when considering whether a lumbar puncture is immediately necessary. While the tool cannot replace clinical judgment or broader diagnostic evaluation, it may help reduce unnecessary invasive procedures in selected low-risk infants.
Reference:
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 08, 2025. doi:10.1001/jama.2025.21454
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