He has the flu.

他患了流感。

youdao

He has been confined to bed with flu for the past couple of days.

他因患流感，已经几天未下床了。

《牛津词典》

Suffering from the flu, he came 8 hours shorter than the 400-day record; his sponsor has gone bust, his girlfriend had left him and his phone and electricity had been cut off.

由于染上感冒，他在还差8小时破400天记录的时候下来；随后发现他的赞助人已经破产，女朋友早拂袖而去，而他的电话和电都被停了。

youdao

He says he has worn it for two days and figures it must be working because he has not come down with the flu.

VOA: standard.2009.04.30

Two of the issues to which he has devoted the most attention since he arrived in the U.S. Senate, avian flu and nuclear nonproliferation, are grand global problems, which, while relatively uncontroversial, are nonetheless risky choices for signature issues, since, in both cases, success is invisible, and failure could mean disaster of world-changing proportions.

NEWYORKER: The Conciliator

For the moment, he said, there is not enough information about the swine flu that has sickened hundreds in Mexico and about 50 people in the United States to accurately forecast how the disease will travel.

CNN: The story

Public health officials are simply assuming that anyone with flu symptoms has swine flu, because it's the only form of the virus in circulation, he said.

CNN: Swine flu goes to college