Keep in mind that you need to be in contact with an infected person's pathogens (bodily Fluids, excretions etc). Merely being in the same room\Plane with someone doesn't pose much of threat. The infection rate of Ebola is less then that of AIDS. While Ebola is transmitted easier then AIDS, the means of contracting it are similar in that you need to have "intimate" contact with an infected person. The good thing is that a person infected with Ebola will show flu like symptoms. As long as you don't share subs, have sexual relations, come in contact with vomit or fecal matter, blood etc you're fine. A sneeze in an airplane won't do it unless that person sneezes in your face.
As far as closing boarders, It makes sense for small nations like Jamaica to impose bans but for the US to do so could make matters worse as others have pointed out. It's better that we be able to screen and track people coming and going rather then them traveling "under the radar".
