What is avian flu
Avian flu among birds 22
There are many different subtypes of influenza A viruses. All know subtypes of influenza A virus, including those that infect humans can be found in birds. Avian influenza refers to influenza A viruses that are found chiefly in birds and these viruses do not usually infect humans. Wild birds are the natural hosts for avian influenza viruses and although they carry the viruses in their intestines they are resistant to infection and do not usually get sick from them. Avian influenza viruses are highly contagious among birds and unlike their wild counterparts, domestic poultry like chicken and turkeys are particularly susceptible to infection and therefore outbreaks of avian influenza in domestic birds are often fatal.
Infected birds shed flu virus in their:
- saliva
- nasal secretions
- faeces
Susceptible birds become infected when they have contact with contaminated secretions, excretions or with surfaces that are contaminated with secretions or excretions from infected birds.
Domesticated birds may become infected with avian flu virus through direct contact with infected waterfowl or other infected poultry, or through contact with surfaces (such as dirt or cages) or materials (such as water or feed) that have been contaminated with the virus. 
Avian flu among humans22
The risk from avian flu is generally low among most people because the viruses do not usually infect humans. However, confirmed cases of human infection from several subtypes of avian flu infection have been reported.
Most cases of avian flu infection in humans have resulted from contact with infected poultry, such as:
- domesticated chickens
- ducks
- turkeys
- surfaces contaminated with secretions/excretions from infected birds
The spread of avian flu viruses from one ill person to another has been reported rarely and the cases are still unconfirmed. The transmission of this infection has not been observed to continue beyond one person.
If the virus mutates to allow easy spread from one person to another, thousands, even millions of people can become infected, resulting in a pandemic.
The symptoms of avian flu may depend on which virus caused the infection. Known symptoms in humans have included:
- typical human flu-like symptoms (fever, cough, sore throat and muscle aches)
- eye infections
- pneumonia
- severe respiratory diseases (such as acute respiratory distress)
- other severe and life-threatening complications
Find out what the differences are between the avian flu and pandemic flu.
Learn why experts are concerned about the avian flu.
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