FebriDx(®): A Rapid Diagnostic Test for Differentiating Bacterial and Viral Aetiologies in Acute Respiratory Infections

FebriDx(®) is a rapid, point-of-care diagnostic test that is designed to aid in the differentiation of bacterial and viral acute respiratory infections (ARIs), thus helping to guide decisions regarding the prescription of antibiotics in the outpatient setting. FebriDx carries a CE mark for use in the EU and is also approved in several other countries, including Canada, Saudi Arabia and Singapore. It is indicated for use in patients > 2 years old with symptoms consistent with a community-acquired ARI. The test involves the use of an immunoassay on a fingerstick blood sample to provide simultaneous, qualitative measurement of elevated levels of C-reactive protein (CRP) and myxovirus resistance protein A (MxA). In two prospective, multicentre studies in patients with acute upper respiratory tract infections, FebriDx was shown to be both sensitive and specific in identifying patients with a clinically significant infection and in differentiating between infections of bacterial and viral aetiology. The test is simple, requires no additional equipment and produces actionable results in ~ 10 min. As was demonstrated in a small, retrospective analysis, FebriDx results can help guide (improve) antibiotic prescribing decisions. Reducing the unnecessary or inappropriate prescription of antibiotics for ARIs of probable viral aetiology is important for antibiotic stewardship and can also reduce the unnecessary exposure of patients to the risk of antibiotic-related adverse events. FebriDx thus represents a useful diagnostic tool in the outpatient setting.