New blood test helps identify bacterial infection in infants with fever

Ann & Robert H. Lurie Children's Hospital of ChicagoSep 8 2016

A blood test used to measure patterns of ribonucleic acid (RNA) expression can help determine if fever in infants under 2 months old is caused by bacterial or viral infection, according to a preliminary study recently published in the Journal of the American Medical Association. For babies with fever brought to a hospital emergency department, this approach might mean avoiding painful testing, hospitalizations and unnecessary antibiotics until potentially life-threatening bacteremia (bacteria in the blood), bacterial meningitis or urinary tract infection can be ruled out.

"Our findings suggest that we can quickly and reliably identify whether an infant has a bacterial infection or not by analyzing RNA biosignatures, which are genomic markers of the child's immune response," said Elizabeth Powell, MD, MPH, study co-author and emergency department physician at Ann & Robert H. Lurie Children's Hospital of Chicago, as well as Professor of Pediatrics at Northwestern University Feinberg School of Medicine. "A simple blood test could replace invasive procedures like a spinal tap."

Typically, physicians evaluate young infants with fever by culturing bacteria from blood, urine and cerebrospinal fluid. Cultures take 24 to 48 hours to establish if bacteria are present.

The study found that the RNA test was highly accurate by comparing results to cultures taken from 279 infants with fever treated in 22 emergency departments participating in the Pediatric Emergency Care Applied Research Network (PECARN). Sixty-six RNA biosignatures distinguished infants with and without bacterial infections, while an additional 10 biosignatures identified whether or not infants had bacteremia.

"We will conduct further research with many more infants to refine and validate test accuracy," said Elizabeth Alpern, MD, also a co-author on the study and emergency department physician at Lurie Children's, as well as Professor of Pediatrics at Northwestern University Feinberg School of Medicine.