To be truthful, the countries that are experiencing the outbreaks had little infrastructure to begin with.
Take a google image tour of Monrovia, Freetown, and Lagos, a mega-city of more than 20 million complete with 8 lane avenues. There are areas in our nation's Capitol that are no better. Seen photos of Detroit lately. Those areas the fire department won't enter. How about the South Bronx, or parts of Brooklyn. You really think that hospitals and medical staff here wouldn't be quickly overwhelmed? This isn't meant to foster panic but a warning to take stock in the ways we are vulnerable. Recall that with all the metal detectors and airport security four US commercial jets were hijacked and we're still paying the price as a result.