Bird flu is an infectious disease among the birds, and this illness occurs worldwide.
When local chickens and ducks get the avian influenza virus, many kinds of wild birds already carry this virus, without showing any symptoms about the danger.
When the avian influenza viruses get inside the birds, they make the birds get avian flu.
There are two different types of avian influenza viruses in chickens. The first types normally cause a mild illness, and the second types are severe and cause death.
The mild illness' symptoms are: the chickens lose their feathers, not give enough eggs, and have little impact on respiratory systems, and they usually stand still. The spreading of this first types of viruses is not severe as in the second types.
In 1878, in Italy, an avian influenza was detected which occurred rapidly, and it spreaded rapidly too, with a mortality that can approach 100% in 48 hours.
This infectious disease, the avian influenza virus, not only affects the respiratory system, but it also invades body limbs, and various cells, and it is called chicken ebola.
Apart from the serious spread among the chickens, the avian influenza virus has already spreaded from one farm to another through the movement of live birds, through people, especially by clothings, shoes, and people's things, the people who are in close contact with the chickens, through vehicles, feedings of the chickens, and putting them in their cages.
These viruses are called H5N1. After the H5N1 avian influenza virus is found in the chickens, the method of prevention from spreading to people is by culling all infected chickens, being careful with your trash, cleaning the farms, and chicken farms, and having stringent sanitation.