We are told not to worry because it takes close contact with an infected person to catch it, but now everybody who knows someone on the plane is at risk?
http://www.reuters.com/article/2014/07/31/health-ebola-transport-idUSL6N0Q570N20140731
Read that.
And this:
http://www.nature.com/srep/2012/121115/srep00811/full/srep00811.html
They may be theoretically at risk, but in reality, they are not.
Yeah, don't worry; be happy.
How quickly to symptoms manifest? Might someone bump into an infected person in an airport elevator and catch the disease even tho the carrier didn't yet know he was ill?
We don't really know that. (We do know that it does not transmit over long distances outdoors). "Close contact" is a term of art that can mean a couple of different things. In a hospital, it means 36"-72" and I'm sure EHF transmits that far, easily.
But the keys to this situation are crowd distances (6'-12') and how infectious contaminated surfaces (blood and vomit) are. If EHF goes 12" and/or if it is persistent on environmental surfaces, once it winds up and lets go in Lagos, it will be very bad.
For example, I could imagine a toilet spreading the virus.