The American that died from Ebola in Nigeria (shortly after getting off a plane from Liberia) was headed home to Minnesota. There were 59 other passengers on that flight, IIRC. I haven’t heard if the Nigerian authorities were able to track them all down, or whether they were quarantined.
I know the infection control coordinator for a hospital in the Washington, DC suburbs. She has told me that they suspect Ebola will actually spread farther, and faster, in developed countries than it does in rural Africa. Paradoxically, it is because Westerners are generally “healthier” than inhabitants of the rural Third World, and we have better transportation infrastructure. In rural Africa, many, if not most, of the infected victims suffer from some co-morbidity with the Ebola. Chronic conditions, such as malnutrition, malaria, anemia, make these victims less robust, and they quickly go from “infected/asymptomatic” to “symptomatic” to “dead”, before they can travel very far. Here in the West, people may have a slightly longer on-set period from “infected/asymptomatic” to “symptomatic”, meaning they will have ample opportunity to travel far-&-wide infecting others before they know they are infected themselves.
P.S. For goodness sake, whatever you do, DON’T watch or read Stephen King’s “The Stand”