The Critical Lens: It is time to start using the right test for febrile young infants.

Fever among infants in the first months of life is a common clinical conundrum facing all clinicians who treat children. Most well-appearing febrile young infants have viral illnesses. However, it is critical to identify those at risk of invasive bacterial infections, specifically bacteremia and bacterial meningitis. Clinicians must balance the risks of missing these infections against the harms of over-investigation. Procalcitonin testing is currently the best diagnostic test available to help guide management, and the Canadian Paediatric Society Position Statement on the management of febrile young infants recommends procalcitonin-based risk stratification. However, in many clinical settings, procalcitonin is either unavailable or has a turnaround time that is too long to aid decision-making. Clinicians who care for febrile young infants must have rapid access to procalcitonin results to provide best-evidence, guideline-adherent care. The wider availability of this test is essential to reduce unnecessary invasive testing, hospitalizations, and antibiotic exposure and could reduce system-wide resource utilization.