Causes of avian influenza A(H7N9)
Explore the cause of avian influenza A(H7N9), how it is spread and where it is found.
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What causes avian influenza A(H7N9)?
Avian influenza A(H7N9) is a new type of avian influenza virus. It has been detected in birds and people in China since March 2013.
Human infection appears to be associated with:
- exposure to live poultry
- contaminated environments in China, including markets where live poultry is sold
How is avian influenza A(H7N9) spread?
H7N9 is thought to be spread to humans from close contact with infected birds.
The majority of people infected with avian influenza A(H7N9) have reported exposure to live birds, mostly chickens. The virus has also been found in:
- ducks
- pigeons
Person-to-person spread of the virus is uncommon based on information gathered from outbreaks in China.