spreading? With a destination travel map? We are talking a matter of days here.

Why it takes hold and spreads faster in certain areas is based on a lot of factors. Size, population density, elderly, etc? Sadly there were cases such as the cruise ship and nursing home in Washington that were soft targets.

But it's not rampaging across China hitting different cities at different times. It's not really doing that in any country, it's just going to have greater impact in some areas as opposed to others.