The spread of avian influenza virus (H5N1) through migrating birds. Poultry such as ducks and geese and gulls and sea birds are carriers of influenza A virus subtype H5 and H7. The virus is carried by birds is less dangerous. Poultry is also a natural reservoir for all influenza virus A.
Species that are sensitive or vulnerable birds infected with H5 or H7 are the types of poultry such as chickens, turkeys, quail, guinea fowl and birds kuau.
As a carrier of avian influenza virus subtype H5 and H7, these birds showed no signs of illness. This is due to H5 and H7 viruses found in these birds is less dangerous and low pathogenicity. This kind of virus only causes a decrease in egg production, broiler weight down. Once inside the body and circulation poultry, influenza A virus will adapt and mutate into a dangerous form within a few months.
It should be noted that the H5 or H7 virus in poultry need to be wary of. Because the virus can live in the human body and mammals such as pigs, cats and horses.