Tiredness and fever are much more likely to be a sign of the flu coming on.

疲倦和发烧很有可能是流感开始的征兆。

《柯林斯英汉双解大词典》

If he's right, it is possible the second, winter wave of 1918 flu was more deadly not because of viral evolution but because bacterial infections are more common in winter.

如果他的假设正确，则在1918年冬天爆发的第二波流感变得更加致命的原因很可能不是因为病毒的演变而是因为细菌感染在冬季更加常见。

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Mexico remains the epicenter of the swine flu outbreak, with more than 150 deaths blamed on the virus.

墨西哥仍然是猪流感疫症爆发的中心，已经有150多人死于猪流感。

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As of Tuesday, seventy-three countries had reported more than twenty-six thousand cases of the new H1N1 flu virus.

VOA: special.2009.06.10

Vietnam has reported more than 2,000 cases of swine flu and so far two patients have died.

VOA: standard.2009.08.25

Although most patients suffer only a mild illness, scores of people are being treated in hospitals and more than 45 people have died because of complications related to the flu.

VOA: standard.2009.07.24

Massachusetts General Hospital has already counted 532 cases of flu among patients, which is more than the Boston hospital saw in any of the previous three flu seasons, spokeswoman Kristen Stanton said Wednesday.

CNN: Flu cases down in some areas; child deaths up

They are more vulnerable to the severe effects of the flu or come into contact more often with this highly contagious virus.

CNN: Flu vaccine attitudes abroad differ from U.S.

Conservative peer Baroness Knight of Collingtree then asked whether the government proposed to fund research into more effective flu vaccines, in the light of the recent report in medical journal the Lancet.

BBC: Peer calls for 'closure' over Lockerbie