Pandemic influenza phases
Through its global monitoring, the World Health Organization can track emerging outbreaks and has the authority to declare the existence of a pandemic
A pandemic is a worldwide epidemic of a disease. The World Health Organization formally categorises outbreaks into different phases. The last global influenza pandemic was the H1N1 swine flu pandemic, formally announced on 11 June 2009. It was declared over on 10 August 2010.
Source: World Health Organization