I was listening to KFI yesterday and they had some microbiologist on who studies pandemics. He said that usually in infections like this, the strain has mutated somewhat by the time it gets to around where we are at. The initial infection will spread like wildfire, but since most mutations are going to be nonviable, it means that the farther down the chain you are, the more likely the virus will end up being a little less contagious, a little less life-threatening.