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Home Topics Infectious Diseases Infections A-Z Avian Influenza

Avian Influenza


Avian influenza is a disease of birds caused by influenza viruses closely related to human influenza viruses. Transmission to humans in close contact with poultry or other birds occurs rarely and only with some strains of avian influenza. The potential for transformation of avian influenza into a form that both causes severe disease in humans and spreads easily from person to person is a great concern for world health.

Avian flu often causes little or no disease in wild waterfowl but sometimes causes large outbreaks associated with high mortality in poultry. In these instances the term 'highly pathogenic avian influenza' (HPAI) is used. This form, which was first recognized in Italy in 1878, is extremely contagious in birds and rapidly fatal, with a mortality approaching 100%. Birds can die on the same day that clinical signs first appear. Outbreaks in poultry may spread rapidly.

Public Health England (PHE) is working with others to protect the UK public from the threat of avian influenza and raise awareness about the disease. Staff across PHE are working with colleagues such as the Department for the Environment, Food and Rural Affairs (Defra) to prepare for avian influenza in UK poultry or birds. For any non-human related avian influenza queries, please go to the Defra website [external link].

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