Discriminating Bacterial and Viral Infection Using a Rapid Host Gene Expression Test

Area of Science:

• Infectious disease diagnostics
• Host response biomarkers
• Molecular diagnostics

Background:

• Host gene expression signatures can differentiate bacterial and viral infections.
• Existing methods lack translation to clinical platforms for rapid diagnosis.
• This study addresses the need for a validated clinical test for infection type.

Purpose of the Study:

• To describe and validate a novel, first-in-class host response test for bacterial/viral infections.
• To evaluate the performance of this test in an independent patient cohort.
• To compare the test's efficacy against procalcitonin and clinical adjudication.

Main Methods:

• Recruited 623 subjects with acute respiratory illness or suspected sepsis from 2006-2016.
• Utilized a 45-transcript signature measured on the BioFire FilmArray System.
• Reference standard was expert panel clinical adjudication, blinded to molecular results.

Main Results:

• The host response test achieved an Area Under the Curve (AUC) of 0.85 for bacterial and 0.91 for viral infection in validation.
• Demonstrated average weighted accuracy of 80.1% for bacterial and 86.8% for viral infections.
• Significantly outperformed procalcitonin (68.7% accuracy) with p < 0.001.

Conclusions:

• The BioFire-based host response test rapidly and accurately discriminates bacterial from viral infections.
• This diagnostic capability surpasses procalcitonin performance.
• The test supports more appropriate antibiotic use by clarifying infection etiology.