Blood test capable of accurately distinguishing between bacterial and viral infections

The results of a large multicenter prospective clinical study indicate that the MeMed, Ltd., (Israel) ImmunoExpert^TM in vitro diagnostic blood test can accurately detect whether a patient has an acute bacterial or viral infection. MeMed’s assay focuses on the body’s immune response to identify the cause of the infection; this is a relatively novel strategy as most infectious disease diagnostics rely on direct pathogen detection. The results of the study, involving more than 1000 individuals, were recently published in PLOS ONE.

Bacterial and viral infections are often clinically indistinguishable, leading to antibiotic overuse, which adds to the spread of antibiotic resistance. On the other hand, the inability to rapidly differentiate infections can lead to the underuse of antibiotics in 20–40 % of patients with bacterial infections. The researchers aimed to improve patient management by providing physicians with a test to distinguish between infections, enabling them to reduce both overuse and underuse of antibiotics.

Eran Eden, Chief Executive Officer of MeMed, commented, “Antibiotic misuse is a pressing public health concern, with devastating healthcare and economic consequences. Rapid, accurate and actionable diagnostic tools are an important part of the solution because they can aid physicians in making better informed treatment decisions. For the past 4 years, our team has been collaborating with leading clinicians and scientists from around the world to develop and validate our novel approach for distinguishing between bacterial and viral infections.”

MeMed’s technology is based on the fact that bacteria and viruses trigger different pathways in the immune system. Researchers carried out a bioinformatics screen to identify putative circulating host immune response proteins. Six hundred possible candidate proteins were then quantitatively screened for diagnostic potential using blood samples from 1002 individuals with suspected acute infectious disease and samples from controls who had no apparent infection. A multiprotein signature was then developed using logistic regression on half of the individuals, with validation carried out on the other half. The signature with the highest precision consisted of three proteins, including both viral- and bacterial-induced proteins.

The research found that the ImmunoXpert immune signature could distinguish between bacterial and viral infections with sensitivity and specificity of >90%. The diagnostic test is said to have outperformed laboratory measurements, clinical parameters, well-established biomarkers and combinations of these tests. Furthermore, the signature remained robust across different physiological systems, times from onset and pathogens. The signature is also unaffected by the presence of potentially pathogenic bacteria that is not causing active disease.

MeMeds ImmunoXpert^TM is approved for clinical use in the European Union and Israel. Additional clinical studies are underway and the company is planning to conduct clinical trials in the US using a specially developed point-of-care platform that is in development.

Sources: Oved K, Cohen A, Boico O et al. A novel host-proteome signature for distinguishing between acute bacterial and viral infections. PLOS ONE DOI: 10.1371/journal.pone.0120012 (2015); New clinical study shows MeMed’s ImmunoXpert^TM blood test can accurately distinguish between bacterial and viral infections.