African countries keep ebola out with border controls http://www.freerepublic.com/focus/f-news/3216118/posts
Nigeria initially banned flights from countries with Ebola but relaxed the restriction once it felt that airlines were competent to take travelers' temperatures and follow other measures to prevent people with Ebola from flying.
Nigeria has teams taking the temperature of travelers at airports and seaports.
So they initially banned travellers, but then backed off and just screened them.