In parts of Asia, where the current poultry outbreaks began in mid-2003, experience has demonstrated the difficulty of eliminating the virus once it has become widely present in birds.

在亚洲部分地方，当前的禽类疫情暴发始于2003年中期。经验表明，一旦病毒在禽鸟中广泛存在，就很难消灭。

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In parts of Asia, where the current poultry outbreaks began in mid-2003, experience has demonstrated the difficulty of eliminating the virus once it has become widely present in birds.

在亚洲部分地方，当前的禽类疫情暴发始于2003年中期。经验表明，一旦病毒在禽鸟中广泛存在，就很难消灭。

youdao