New blood test distinguishes bacterial and viral infections in newborns

Researchers at the IRCCS Istituto Giannina Gaslini in Genoa, Italy, have developed a rapid blood test capable of distinguishing between bacterial and viral infections in newborns. Presented at the European Emergency Medicine Congress, the test analyzes the levels of two proteins on white blood cells: CD64, which is linked to bacterial infections, and CD169, which is associated with viral infections.

Fever in infants under three months is a critical medical concern due to the risk of life-threatening infections. Currently, doctors often face a diagnostic dilemma where standard biomarkers can cause false positives, leading to unnecessary antibiotics, hospital admissions, and invasive procedures like lumbar punctures. The new test uses the ratio of these two markers to provide high accuracy in approximately 15 to 20 minutes.

In studies involving infants, the test helped identify whether antibiotics were necessary, potentially reducing the misuse of medication that contributes to global antibiotic resistance. Only about 15% of febrile infants typically have serious bacterial infections, making precise differentiation vital for clinical management.