My intent in the example was to stop the people form those nations infected from boarding an aircraft and traveling to my nation and spreading the infirmity. Either that or place them in quarantine upon arrival.
Ever since this ebola epidemic first broke I have been an advocate of travel bans.
Mandatory quarantines are a good idea too, and it should definitely be longer than the average incubation period of 21 days since average means it can take longer and what if people first get infected when they are on the plane?
A mandatory quarantine period of 30 days for people who have been to the affected countries in the past 30 days would provide a good cushion.
Fellow passengers will have to be quarantined too. People subject to the quarantine due to their own travels should also be publicly identified. This would be a good way to minimize spreading the infection to the general population and put social pressure on the selfish and irresponsible people who have been to those countries and choose to then travel elsewhere.
I don't know what the visa requirements are for the affected countries but if a visa is required to travel to those countries then that is one way to determine if someone has been there in the past 30 days.
Medical personnel can be sent to the affected countries to help fight the epidemic, that is their job afterall, but sending anyone else there to do any other kind of work, including troops to help build facilities etc is taking an unnecessary risk.
As much as I value building goodwill for the US internationally, putting more of our people and possibly the whole country at risk with a deadly epidemic is not a good way to do it. Send money or other resources to locals to do the work. I give the Obama administration a big fat "F" for its strategy in handling the ebola outbreak.