New Technology Enables Differentiation of Bacterial and Viral Infections

With the COVID-19 pandemic still in full swing and flu season on the way across much of the US, clinicians need tools for differential diagnosis.

This tool could be in preparation. On September 20, the Food and Drug Administration (FDA) approved the MeMed BV test on the MeMed Key point-of-need platform for use in children and adults. The technology is designed to help healthcare providers differentiate between bacterial and viral infections and hopefully limit inappropriate prescribing of antibiotics.

“For those of us who care for acutely ill children, we have been waiting decades for accurate and rapid diagnostics to confidently control the care of moderately ill children with no clear focus of infection or identifiable viral disease,” said Rich Bachur, MD, Professor of Pediatrics and Emergency Medicine, Harvard Medical School, and Chief, Division of Emergency Medicine, Boston Children’s Hospital, said in a company press release. “This new test promises to differentiate children with self-limiting viral diseases from those with possible bacterial infections and thus to support the careful use of antibiotics.”

According to the company, MeMed BV decodes the body’s immune response to infection, the “host response,” rather than just detecting the presence of a microbe. This enables a robust diagnosis when the infection site is inaccessible or unknown, even when the pathogen is undetectable with traditional testing, or when new pathogens emerge as the cause of the infection, enabling more informed antibiotic prescription decisions.

The technology identifies a “host protein signature” using both virally and bacterially induced biomarkers: tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), interferon-gamma-induced protein-10 (IP-10) and C-reactive Protein (CRP). In a study with samples from 175 patients with viral and 139 with bacterial infections, the signature sensitivity was 93.5% and the specificity 94.3%. Both were significantly higher than the values for CRP, procalcitonin, interleukin-6, human neutrophil lipocalin, white blood cell count, absolute neutrophil count, and prediction rules. In addition, the signature was identified as viral 50 of 57 virus patients prescribed antibiotics.

More recently in a to learn which has been published on a preprint site and has not yet been assessed, the area of the signature under the Receiver Operating Characteristic Curve (AUC) for the precise identification of patients infected with SARS-CoV-2 was 0.86. This performance was superior to IL-6 (AUC 0.77) and CRP (AUC 0.78). Additionally, the signature differentiated patients who continued to get worse after achieving a severe outcome from those who improved and predicted 14-day odds of survival, the researchers said.

As promising as the technology is, clinicians would love to see how it performs in larger clinical trials before putting it into clinical practice.

“Does it specifically differentiate COVID-19 from other respiratory viral infections like flu, RSV, the well-known circulating coronaviruses like OC43, etc.? If so, then it could be useful, ”said an epidemiologist and infectious disease specialist infection on condition of anonymity. “If not, what do I do with the result without further testing?”