Statistics from NSW Health have confirmed the clinical impression of many North Coast GPs that the flu season has hit early this year. They report the predominant strain is influenza A (H3N2) but levels of influenza B have also increased in recent weeks.
While the symptoms of influenza are similar to many viral infections with sore throat, cough, nasal discharge and blockage, the high temperatures, lethargy and myalgia of influenza that last for four or five days have been common presentations in recent weeks.
The availability of PCR testing for viral antigens on nasal and throat swabs has been a significant advance in the rapid diagnosis of respiratory tract infections. However the clinical utility of this testing is lessened as the prevalence of influenza rises in the general community.
Antiviral treatment in the form of oseltamivir (Tamiflu) and zanamivir (Relenza) have been available for some years. These agents have limited value shortening the period of symptoms by 24 hours. This is mainly of clinical utility to patients with significant risk for progression to influenza's life threatening complications. The high cost of these medications may be justified in patients with COPD and congestive heart failure. In such patients the medication should be started at the time of diagnosis and not await laboratory confirmation.
Data from Sullivan Nicolaides pathology confirms the rapid rise of influenza in southern Queensland. Fortunately, NSW Health reports the recent strains are covered by the current vaccination, so patients, particularly the elderly at risk, can still benefit from vaccination this late in the season.