According to this Reuters article (http://preview.msn.com/en-us/news/us/first-ebola-case-diagnosed-in-the-united-states-cdc/ar-BB6EA9s ), he’s not likely a US citizen. Which begs the question of how he was exposed and why he traveled after a known exposure.
Travel restrictions in to/out of affected regions should have been imposed months ago until this was under control as clearly not all people can be trusted to do the right thing.
Once word got around that those two American doctors were brought here and survived, it became inevitable that other infected people, who had the means, would come. And, will continue to come. Everybody wants to live.