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Influenza

A nurse fits a protective mask on a doctor in a Jakarta hospital

Influenza is a viral infection that affects mainly the nose, throat, bronchi and, occasionally, lungs. Infection usually lasts for about a week, and is characterized by sudden onset of high fever, aching muscles, headache and severe malaise, non-productive cough, sore throat and rhinitis.

The virus is transmitted easily from person to person via droplets and small particles produced when infected people cough or sneeze. Influenza tends to spread rapidly in seasonal epidemics.

Most infected people recover within one to two weeks without requiring medical treatment. However, in the very young, the elderly, and those with other serious medical conditions, infection can lead to severe complications of the underlying condition, pneumonia and death.

Pandemic (H1N1) 2009 is a new influenza virus that has never circulated among humans before. After outbreaks in North America early in 2009, the virus spread rapidly around the world. Pandemic influenza is transmitted like seasonal influenza but people have virtually no immunity to it. Mitigating its effects is a public health priority.


GENERAL INFORMATION

Fact sheet on influenza

Fact sheet on avian influenza

Ten concerns if avian influenza becomes a pandemic

RELATED TOPICS

- Pandemic (H1N1) 2009

- Disease outbreaks: influenza

- Avian influenza

- Infectious diseases

- Vaccines

- Vaccines safety

TECHNICAL INFORMATION

Recommendations for influenza vaccines

- More about influenza

PUBLICATIONS

Options for the use of human H5N1 influenza vaccines and the WHO H5N1 vaccine stockpile

- More publications on influenza

STATISTICS

FluNet


WHO PROGRAMMES AND ACTIVITIES

Global Influenza Programme
INFLUENZA IN WHO REGIONS

Region of the Americas
European Region
Western Pacific Region


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