Immune-Marker Blood Test Identifies Bacterial Infections in Febrile Infants Within 15 Minutes

Hospitals routinely administer broad-spectrum antibiotics to febrile neonates pending culture results that take 24-48 hours, driving resistance and microbiome disruption. The assay quantifies CRP, procalcitonin, and an interferon-stimulated gene product via microfluidic cartridge. In the prospective cohort at three US children's hospitals, bacterial cases showed elevated CRP-procalcitonin ratios while viral cases upregulated the gene signature within 15 minutes of venipuncture.

Current guidelines from the AAP still recommend empiric treatment for well-appearing febrile infants, yet observational data indicate only 5-10% harbor serious bacterial infection. The new test addresses diagnostic uncertainty that fuels overtreatment but was not compared against RNA-based classifiers already validated in older children. Implementation barriers include cartridge cost and the need for point-of-care platforms in community emergency departments.

Next steps require a 1,000-infant randomized trial measuring antibiotic-days avoided and safety endpoints before FDA 510(k) submission. Parallel work in low-resource settings will test whether dried-blood-spot versions retain performance when cold-chain logistics are absent.