Skip to main content
hpa logo
Topics A-Z:
Search the site:
Home Topics Infectious Diseases Infections A-Z Influenza

Influenza

Generic influenza virion, cutaway view

Influenza or 'flu' is a respiratory illness associated with infection by influenza virus. Symptoms frequently include headache, fever, cough, sore throat, aching muscles and joints. There is a wide spectrum of severity of illness ranging from minor symptoms through to pneumonia and death.

Seasonal influenza

This section contains guidance, epidemiological data and information for the current or most recent influenza season as well as historical information on past seasons.

›› Seasonal influenza

Pandemic influenza

This section is in two parts. The first part contains guidance and information concerning planning arrangements around a future pandemic. The second part includes information on the recent H1N1 (2009) 'swine flu' pandemic as well as background information on the major pandemic events of the 20th century.

›› Pandemic influenza

Avian influenza

This section contains information on avian influenza and guidance relating to avian influenza incidents.

›› Avian influenza

Influenza in animals

This section contains background information about influenza in animals and the risk posed to human health.

›› Influenza in animals

Further information