Real-World Utility of the Host-Response MeMed BV Test in a Pediatric Emergency Department: A Non-Randomized Study...

Background: Differentiating between bacterial and viral infections in pediatric emergency care is challenging, often leading to unnecessary antibiotic use. The MeMed BV (MMBV) test is a host-response assay designed to differentiate bacterial from viral infections, but real-world data in pediatric settings remain limited. Methods: We conducted a pragmatic, single-center, prospective cohort study to assess the clinical utility of MMBV in children with acute respiratory infections or fever without source. Patients were assigned to standard of care (SOC) or MMBV testing (SOC+MMBV) based on time of presentation to the emergency department. The primary outcome was antibiotic prescribing. Secondary outcomes included diagnostic test utilization, hospitalization rates, and length of stay. Analyses were stratified by hospitalization status, clinical severity [National Institute for Health and Care Excellence (NICE) traffic light system], and patient age. Results: From July 2023 to April 2024, 343 patients were enrolled (171 SOC, 172 SOC+MMBV). In the SOC+MMBV arm, reduced antibiotic prescribing was observed among outpatients and those with non-severe signs and symptoms. Antibiotic prescribing was significantly reduced in children under five years with a low-risk profile, according to the NICE traffic light system (26.3% vs. 7.5%; p = 0.034). Multiplex PCR testing was significantly reduced in the SOC+MMBV group (28.7% vs. 16.3%; p = 0.006) compared to SOC for both inpatients and outpatients. No significant differences were observed in overall diagnostic test use or length of stay. Conclusions: MMBV improved antibiotic and diagnostic stewardship in a real-world pediatric ED setting, significantly reducing unnecessary antibiotic use among low-risk children under five and minimizing unnecessary multiplex PCR testing across the cohort.