Cheerful--
You ought to take a public health class after you take your first level microbiology and virology classes... These classes explain why the movie was dead wrong on viral transmission. But it is on point about what US AMRID will do if such a situation existed--i.e. nuking the place...
You should watch Legend with Will Smith if you liked Outbreak.
Also, the reason why viruses spread so far is because of filth and no controls on public health. It is conceivable that it could happen today with a different kind of virus unseen, because it did happen with Bird Flu (H5N1 strain). But Dr. Fauci literally stated a catastrophe of the situation to the Bush Admin to put more money in Global Public Health. Also there are now 3 strains of HIV in humans...
Some people are just plain nasty and funky... I am not talking about poor countries--I am talking about folks who live in the US.
Besides, if someone showed up with major quarantined viral infection and the physicians were astute enough (

), the "Andromeda Strain" protocol would be in effect... Now, that is a book and movie you should try to see.
It is thought the reason why Egyptian, Roman and European pestilences were devastating was due to water source contamination including chemicals and microbial-fecal contaminations; poor water treatment options and poor sanitation practices--cleaning out the leavened grain areas, etc.
Today if that same kind of thing were to happen in the US... Well, it already does and public health departments are sorely understaffed.