Health conditions

Influenza (flu) pandemic

For up-to-date information on the current coronavirus (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 flu is a global outbreak of flu. This occurs when a new strain of the flu virus, against which people have little or no immunity, spreads rapidly from person-to-person.

Pandemic flu virus may cause illness of varying severity.

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

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

Pandemic flu in Australia

There have been several 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 flu 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 flu, visit Smartraveller (external site) to find out more information.


  • Pandemic flu is different to seasonal flu in that it usually involves a new strain flu virus (or a past strain from many years ago). The result is that most people will have immunity to this virus.
  • Pandemic flu is a worldwide outbreak of a flu virus in the human population.

Last reviewed: 20-03-2020
Public Health

See also

Link to HealthyWA Facebook page