Flu season in the U.S. is particularly bad this year, and a new branch of the flu family tree may be to blame.

In a striking real-world experiment, flu patients spent days indoors with healthy volunteers, but the virus never spread.

Flu is surging across most of the U.S.

The U.S. is facing its worst flu season in 25 years, according to the Centers for Disease Control and Prevention, which ...

The new influenza strain is highly contagious, but how deadly it is? How many deaths it has caused so far?

Influenza is surging in New Hampshire, and the number of people being taken to the hospital for it is setting new records.

This year's flu season is turning out to be brutal. As a new variant known as subclade K spreads rapidly, a study out today ...

So far, 12 people have died from the flu this season, according to the latest data from the New Hampshire Department of ...

Since late June, San Diego County has recorded more than 5,200 flu cases.