Peg,
SARS is a virus. Specifically according to the CDC: Scientists at CDC and other laboratories have detected a previously unrecognized coronavirus in patients with SARS. The new coronavirus is the leading hypothesis for the cause of SARS, however, other viruses are still under investigation as potential causes.

Admittedly from a distance, I have been trying to find the real information. It seems to me that the media swings between over-hype and possibly false assurances. It's not safe to travel to Toronto one moment & no need to cancel that conference the next. CDC SARS information
is constantly being updated with the latest information.

I think comparisons to influenza are useful simply because that's the main reference we have for getting a handle on it. It strikes me that saying one is worse than the other is not very helpful just now.

I don't for one minute believe the statistics coming from China. I think it is being way under recognized & as a consequence under reported.