Influenza rapid tests – advantages and limitations / Influenza-Schnelltests – Vorteile und Grenzen

Abstract

Abstract The recent advent of new treatments (neuraminidase inhibitors) for influenza has stimulated the development of rapid diagnostic methods because these treatments have shown a clinical benefit only when administered early in the course of the disease. In Germany, at least ten different rapid enzyme-linked immunosorbent assay kits are available as “near patient test” for the diagnosis of influenza viruses. Classical viral culture methods and immunofluorescence staining of antigens in patient specimens were used in most studies as a reference to analyze the performance of rapid influenza tests. The different tests had sensitivities ranging from 50 to 96% and specificities ranging from 72 to 100%, respectively. The test characteristics mainly depended on the type of test, the type and processing of clinical specimen, and the age of the patient. Although the sensitivity of the rapid diagnostic tests is lower compared to that of virological and molecular methods, the positive predictive values indicate that rapid testing may be helpful for patient management, including the prompt administration of appropriate antiviral therapy, as well as for assistance in isolating patients in hospitals and long-term-facilities to reduce the spread of infection and for the surveillance of influenza.