The biggest danger is Lagos, Nigeria. Twenty million people live there under deplorable conditions, 2/3 of Lagos are slums with poor sanitation. If it gets loose, 10 million will die there alone. Nigeria does not have the medical facilities to handle an epidemic and more importantly isolate all the ebola patients they would have if it gets loose in Lagos. If an epidemic hits Lagos the population will flee the city. They will become multiple vectors for the disease. The same can be said for most large cities in the 3rd world.
Yup, Rio, calcutta, delhi, mexico city, the caribbean, central america......not a good thought.