A Digital Microfluidic Sepsis Diagnostic Predicts Bacterial Infection Status Using Host Transcription Response

Early diagnosis of sepsis is critical due to its long-term health consequences and high mortality rate. However, typical diagnostic procedures for suspected sepsis, such as blood cultures, take hours to days to yield results. Differentiating between bacterial infections and illnesses caused by other etiologies is necessary to inform appropriate intervention, including the decision to administer or withhold antibiotics, and to prepare the warfighter to return to service. A rapid diagnostic test that predicts the likelihood of bacterial infection in suspected sepsis cases can help guide clinicians to appropriate treatment, reduce unnecessary antibiotic use, and help curb antimicrobial resistance.

In this poster presented at the Military Health System Research Symposium (MHSRS) 2024, we introduce a digital microfluidic (DMF) assay run on a point-of-care device and cartridge that differentiates bacterial infection from non-bacterial illness using a panel of 10 mRNA targets. We demonstrated the feasibility of a point-of-care transcriptomic host response assay that discriminates bacterial infection from non-bacterial illness, achieving 80% positive predictive accuracy (PPA) and 90% negative predictive accuracy (NPA) by analyzing 10 host mRNA markers from a single drop of blood (<50 μL).

This research was done in collaboration with Duke University School of Medicine, and we envision that the DMF Host Response Assay could serve as a complementary diagnostic tool for assessing suspected sepsis cases, providing significant clinical information hours to days earlier than traditional blood cultures, and helping to reduce unnecessary antibiotic usage in military settings.