Rapid Diagnosis of Influenza

Abstract

Much effort has been expended developing testing modalities for influenza viruses that are capable of providing rapid results to clinicians. Antigen-detection techniques, historically the only methods able to deliver results quickly, are still widely used despite concerns about sensitivity. Recently, nucleic acid amplification tests (NAATs), which can achieve rapid turnaround times and high sensitivity, have become available. In addition, NAATs can detect other respiratory pathogens. Although there are many theoretical advantages to rapid influenza testing, the clinical impact of testing in various patient populations must be considered against the cost and the analytical performance of the tests.

Performance of the Molecular Alere i Influenza A&B Test Compared to That of the Xpert Flu A/B Assay

“…During the pandemic H1N1 outbreak of 2009, the performance of rapid antigen detection tests for influenza was shown to be inferior to the performance of molecular methods, with sensitivity ranging from 10% to 70% (1)(2)(3). Rapid molecular testing was not available in many hospitals, clinics, and physician offices due to either cost of equipment or cost of reagents, use of complex molecular diagnostics requiring skilled technologists to perform testing, and/or slow turnaround time to results (2,4,5). Recently, the Alere i influenza A&B assay (Alere, Scarborough, ME) became a FDA-cleared molecular test for detection of influenza viruses A and B.…”

Evaluation of the Alere i Influenza A&B Nucleic Acid Amplification Test by Use of Respiratory Specimens Collected in Viral Transport Medium

“…For these reasons, many clinical laboratories employ rapid antigen-based assays as their first-line diagnostic test for influenza virus infections. Though generally exhibiting very high specificity and positive predictive values, the major limitations of currently available rapid antigen tests involve their low and widely variable sensitivity (19).…”

Targeting eicosanoid pathways in the development of novel anti-influenza drugs

“…The adamantanes, amantadine and rimantidine, block the IAV M2 protein ion channel and viral uncoating. However, because of widespread viral resistance, these drugs are no longer recommended [2]. Neuraminidase inhibitors, oseltamivir (Tamiflu) and zanamivir (Relenza), as well as peramivir and laninamivir, are now being commonly used and stockpiled (e.g., 14.6 million courses of oseltamivir in the UK) in anticipation of a new pandemic.…”