Is it possible for something like the scenario featured in the 28 Days Later or The Crazies to occur ? An epidemic that affects a local area that could have the potential to spread regionally, nationally and world wide eventually.
Perhaps a human form of the mad cow disease called Creutzfeldt–Jakob disease combining with other virus or perhaps a new virus either conceived naturally or concocted in a laboratory. That new virus causes extreme psychosis and spreads by contaminated liquid in the form of saliva, blood and other bodily fluids.
Will an airborne variant be more dangerous ?
Will the incubation time of the disease help in the spread of the virus? A slow incubation time results in those infected being able to travel without visible symptoms showing in the early stages, thus allowing the quick spread of the disease world wide due to global air travel.
In the event of a global epidemic break out, what will be the safe buildings, locations and areas to survive in ?