One of the things that worries me about SARS is the apparent variability in how contagious it is and what it's mortality rate is. Canada unfortunately seems to have a particularly bad strain; of 103 cases, 13 have died, a lot higher than the often quoted 4% mortality rate.

Also, it sometimes seems to be able to get past even tight infection-control procedures - anurse at a local hospital has developed SARS and is in isolation, plus 30 or so contacts are in quarantine. (the suspected case at my own hospital turned out not to be SARS, which was a relief; authorities are trying to be very conservative in their handling of suspected cases).