Health conditions

Influenza (flu) pandemic

For up-to-date information on the COVID-19 pandemic.

What is a pandemic?

A pandemic occurs when a disease or virus becomes geographically widespread throughout the world.

What is pandemic influenza?

Pandemic influenza is a global outbreak of influenza.

Pandemic influenza is different to seasonal influenza in that it usually involves a new strain of influenza virus (or a past strain from many years ago), against which people have little or no immunity, spreads rapidly from person-to-person. The result is that most people will have immunity to this virus.

Pandemic influenza virus may cause illness of varying severity.

Some pandemic viruses have caused illness of similar severity to that seen with seasonal influenza.

However, because more people catch the influenza during a pandemic than in a usual year, there are higher overall numbers of people requiring hospitalisation or in severe cases, dying.

Pandemic influenza in Australia

There have been several influenza (flu) pandemics that have affected Australia, including the Spanish flu (1918), Asian flu (1957) and the Hong Kong flu (1968).

The most recent was the 2009 swine flu pandemic.

Coronavirus (COVID19) pandemic

On 11 March 2020, the World Health Organization (WHO) (external site) declared the coronavirus, COVID-19, a pandemic.

Find out more information about the COVID-19 pandemic.

More information

If there is an outbreak of pandemic influenza in your community

  • Check HealthyWA for updates.
  • Watch TV, listen to the radio or check newspapers for up-to-date information.

Pandemic outbreaks in foreign countries

If you are travelling to or residing in a country that may be affected by pandemic influenza, visit Smartraveller (external site) to find out more information.

Last reviewed: 20-03-2020
Public Health
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