Evaluation of a novel host protein-based assay for ruling out bacterial infections in patients with suspected respiratory tract infections at an urban academic hospital.
Academic Article
Overview
abstract
OBJECTIVE: Distinguishing bacterial from viral respiratory infections is challenging in Emergency Department (ED), driving diagnostic uncertainty and antibiotic overuse. The MeMed BV test measures three host protein markers and combines them into a single numeric score. This study evaluates its analytical and clinical performance and assesses its potential to improve antibiotic stewardship. METHODS: Remnant serum samples were obtained from 176 ED patients presenting with respiratory infection symptoms and/or unexplained fever who had either a positive respiratory pathogens panel, bacterial culture, or elevated procalcitonin (PCT ≥ 0.25 ng/mL). MeMed BV test was performed. Demographic, clinical information, and laboratory data were obtained via chart review. Infections were adjudicated by an attending ED physician and resident. RESULTS: Analytical validation demonstrated robust linearity and precision, and stability extending beyond the vendor's stated claim. Overall, 107 (60.8 %) patients were adjudicated as having viral/non-bacterial infections, and 69 (39.2 %) as bacterial/co-infections. MeMed BV achieved a sensitivity of 93.8 % (95 %CI: 84.5-98.3 %), specificity of 72.9 % (95 %CI: 63.9-81.2 %), positive predictive value (PPV) 69.8 % (95 %CI: 60.1-79.5 %), and negative predictive value (NPV) 94.6 % (95 %CI: 86.7-98.5 %). It displayed the highest sensitivity and NPV for differentiating bacterial/co-infections, whereas white blood count (WBC) and PCT showed the highest specificity and PPV, respectively. Among 44 viral/non-bacterial cases that received antibiotics, MeMed BV flagged 24 (54.5 %) as viral/non-bacterial infections. CONCLUSION: The MeMed BV test is a rapid, reliable diagnostic tool for differentiating bacterial/co-infections from viral infections, offering a high NPV to rule out bacterial infections. Its implementation in ED could support antibiotic stewardship by reducing unwarranted antibiotic use.
