Swine flu is no joking matter, so I’ll keep this one short and to the point, and just comment that the spread of the virus (or, for that matter, any virus) is another example of a stochastic system. Partly predictable, and partly random. The spread of viruses such as SARS have been well studied by mathematicians and physicists, and, I strongly imagine, there are physicists who are right now analysing the way the current outbreak is developing.
That, I am well aware, will be of little comfort to those who have or suspect they have the virus.