This year to date, the influenza season which started in the week of the 29th of May 2017 has been predominated by influenza A(H3N2) virus. However, there is sporadic circulation of A(H1N1)pdm09 and influenza B. To date there is nothing unusual about the 2017 influenza season. Influenza A(H1N1)pdm09 previously known as the “swine flu” has been circulating as one of the influenza seasonal strains since 2010.
Persons who have been diagnosed with this strain during the influenza season should be managed as is usual for influenza. No specific public health intervention should be instituted for contacts of patients in whom influenza A(H1N1)pdm09 is identified. In the majority of otherwise healthy young persons, influenza is an uncomplicated infection, and in rare events healthy individuals may present with severe influenza illness or complications. Complications of influenza, e.g. pneumonia, are more common in pregnancy, in persons over 65 years of age, those with other health conditions, for example those affecting the heart or lung, diabetics or persons with a weakened immune system.
It is recommended to get vaccinated for influenza before the start of the influenza season. However, it is never too late to vaccinate – especially when influenza is still circulating, and particularly for persons at risk of severe illness and complications.
It is also important to note that during the influenza season other circulating respiratory viruses may also cause respiratory illness. These include respiratory syncytial virus (RSV), adenovirus and rhinoviruses. Health practitioners should consider influenza in their differential diagnosis for patients presenting with influenza-like illness or patients admitted with a lower respiratory tract illness.