running a flu or having a flu

flu   Tue Dec 23, 2008 1:55 am GMT
as above
K. T.   Tue Dec 23, 2008 2:09 am GMT
I don't know what they say in GB, but any of the following are okay to me:

He's running a FEVER.
He has the flu.
He has a fever.
We are having a FLU epidemic/FLU outbreak in our schools right now.

These are common. I have heard other ways of expressing this.