The problem, the consequences, and rapid testing solutions
Each year, influenza (flu) causes serious infection and death around the globe, usually in the winter months (seasonal influenza). Latest figures suggest that worldwide, these annual epidemics result in about three to five million cases of severe illness, and about 250,000 to 500,000 deaths.1
The Problem
Influenza symptoms are similar to those of other common respiratory infections. Patients presenting with these symptoms are commonly treated empirically, without a formal diagnosis.
The problem in relation to antimicrobial stewardship is twofold. Patients with Influenza-Like Illness (ILI), a medical diagnosis based on symptoms alone, are often treated with antibiotics, even though the most common cause for this set of symptoms is influenza, a viral infection. Antibiotics are not effective against viruses.
Alternatively, these patients are often automatically prescribed with influenza antivirals, which will be unnecessary if influenza is not the cause of infection and are only effective if prescribed within 48 hours of onset of symptoms.

The Consequences
Resistance to influenza anitivirals is emerging. Many strains of influenza have already developed resistance to the older class of flu antivirals, the adamantanes. After four decades of effective use in the prophylaxis and treatment of influenza, global resistance to these drugs has increased dramatically among influenza viruses of the A/H3N2 subtype in recent years.2
The new class of influenza antivirals, neuraminidase inhibitors, oseltamivir (Tamiflu) and zanamivir (Relenza), are currently suitable for all strains. However, sporadic resistance has already been observed with oseltamivir, and we have no further line of defence currently. During the 2007-2008 influenza season, oseltamivir resistance among influenza A(H1N1) viruses increased significantly for the first time worldwide.3