The virus Alert system keeps an eye on the websites customers visit to stop them accidentally going to places riddled with viruses.

病毒预警系统会监测客户浏览的网站以防止其意外地链接到充塞着病毒的处所。

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Swine flu has become the world's first official pandemic in 41 years after the world Health Organisation raised the alert level on the H1N1 virus from phase 5 to 6, the highest on the scale.

世界卫生组织宣布将甲型H1N 1流感病毒的警戒级别由5级提升至最高级别6级，至此，猪流感已成为41年来世界上第一个正式的全球大流行病。

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But I insist that the virus is still present, that we need to remain on alert and the resumption of activities will be little by little, not all at once.

但是我坚信流感现在仍然活跃，我们需要继续提高警惕，病毒的反扑是一点一点体现出的，而不是一下子爆发。

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The World Health Organization says it needs to see clear evidence of sustained community transmission of the swine flu virus from person-to-person in at least two regions of the world before it raises its alert to the phase six pandemic level.

VOA: standard.2009.05.14

"This is a form of digital extortion, " said the BKA in its alert about the virus.

BBC: Ransomware page

Scottish livestock producers have been put on high alert after a virus affecting cattle and sheep was detected in northern England.

BBC: Schmallenberg virus: Scottish farmers put on high alert

According to Reuters, the World Health Organization (WHO) originally issued an international alert in late September saying a virus previously unknown in humans had infected a Qatari man who had recently been in Saudi Arabia, where another man with the same virus had died.

FORBES: Is a New SARS-like Virus Spreading in the Middle East?