Swine influenza (swine flu) is an acute viral infection of the respiratory tract in pigs caused by type A influenza virus.

猪流感是一种发生在猪身上的高度传染性急性呼吸道疾病，由A型流感病毒引起。

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The flu, or influenza, is caused by a virus that affects the respiratory system.

流感是有病毒引起的呼吸系统疾病。

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In the United States, cases of suspected influenza are at higher numbers than usual this early in the flu season.

VOA: special.2009.11.24

You've got the flu, you've got influenza in your upper respiratory tract, your cells are making more influenza.

你就此得了流感,你得了上呼吸道流感,你的细胞正在制造更多流感病毒

耶鲁公开课 - 生物医学工程探索课程节选

Viruses, you know about viruses; variola, we're going to talk about next week which causes smallpox, influenza, which causes the flu and HIV of course which cause AIDS are some examples.

病毒 你们都知道病毒,像天花病毒,我们下周会讲的引起天花的病毒,还有引起流感的流感病毒,引起艾滋病的人类免疫缺陷病毒等等

耶鲁公开课 - 生物医学工程探索课程节选

The site monitors search terms for words such as influenza and flu.

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I'm glad you are thinking about ways to protect yourself from the flu (influenza) since the flu season can continue as late as May of each year, and immunization can prevent or lessen the severity of a case of the flu.

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Swine influenza, or flu, is a contagious respiratory disease that affects pigs.

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