Avian influenza, also called bird flu, is an infection in birds caused by several strains of influenza A virus. Avian influenza is found in bird populations worldwide and some of these strains have spread from wild birds to domestic poultry. Some specific viruses (e.g. H5, H7 and H9 strains) have also spread from infected birds to humans, although this is usually rare.
In recent years, human cases have been reported in a limited number of countries, with most previous cases reported from China, South East Asia and Egypt, usually following exposure to avian species. However, human cases associated with international travel are very unusual. Check our Country Information pages for recent destination specific news and outbreaks.
In humans, avian influenza symptoms vary, depending on the virus strain. Symptoms range from a mild flu like illness, sometimes with conjunctivitis (red, sore, discharging eyes), diarrhoea and abdominal pain, to a severe respiratory illness with breathing difficulties and pneumonia. Human infections may be fatal.
Human infections are mainly associated with direct contact with infected birds or through indirect contact (contact with body fluids, including blood or bird droppings) in places where infected birds have been kept (e.g. poultry farms, bird markets). Transmission from human to human is very infrequent.
Close, prolonged contact with an infected bird is usually needed for bird flu to spread to humans, so all travellers should:
Seek prompt medical advice if you become ill with severe breathing difficulties within 10 days of travel to any country affected by avian influenza outbreaks.
The seasonal flu vaccine available in the UK from September/October each year will not prevent infection with avian influenza viruses.
Antiviral medications may be used, after specialist advice, to treat cases or suspected cases of avian influenza.
See Public Health England’s website for more information on avian influenza.