The cause of bird flu (also known as bird flu or "bird" flu) by the virus, usually infected birds, but are not normally used, was known to some of the infected pigs and "cats."

禽流感(也称为禽流感或禽流感)是由病毒引起的，通常感染鸟类，但不常用，一直被称为感染猪和一些猫。

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The virus is usually passed on through close contact with infected birds and their feces.

禽流感病毒主要是通过密切接触患病的禽类以及它们的排泄物而感染的。

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Experts say that cross-infection to humans is still relatively rare and usually occurs where people have been in close contact with infected birds.

BBC: NEWS | Africa | Africa bird flu disaster warning