Bar-Yam is about 65% correct IMHO. Looking at the diagrammatic growth ( assuming it is derived from his mathematical model) he needs to significantly increase the number of variables linking where necessary to some appropriately framed random number generators. It is through convergences of seemingly random events leading from other events such as a funeral or a sufferer walking though a crowded market place that may or may not spread the infection on any particular occasion. Mathematicians need to get input from a variety of medical, community, NGO and development agency collaborators to MAKE the model realistic.
Anecdotally the virus has not mutated sufficiently to be a significant risk for people in developed or indeed emerging countries. It has mutated sufficiently to race thorough the crowded slums of Africa.
Airline travel between West Africa and more developed countries doesn't present too much of a risk and it is pretty easy to exclude people with a fever from flights. I agree that travel between African locations may be more problematic from a disease control perspective HOWEVER people who can afford airline travel (and their primary contacts) may not be an at risk group. A model needs to put numbers on all of this.
