Nurses (in the US) who treated Ebola patients (who contracted Ebola abroad and then flew into the US) were infected with Ebola by their patients. Being an advanced nation, major medical resources were at hand to prevent the further spread of disease.  No one told the nurses (or the patients) to go ride the subway and spit on people or to go to the supermarket and sneeze on all the fruits and vegetables. We don't know for sure, but the treatments and precautions may have helped to prevent the spread.
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Some markets are probably more worrisome than others. NYC has two large Chinatowns and 3 international airports ... and Chinese AMPs.  I am guessing that LA also has lots of international travelers from China looking to unwind after a long flight.  I'm thinking that Wausau, WI (Wausau: That's USA with a WA up front and a U at the end.) isn't as risky (although I think there is a large Vietnamese population there).