In the meantime, in the US, fewer than 1 case per year from the time the virus was discovered until the recent outbreak. This would indicate the virus is far more prevalent in Central and South America than it has been in the US, up until the same time frame that 'unaccompanied illegal immigrant" children were admitted wholesale into the US and distributed over the country.
Again, correlation, but a tighter fit. Investigating to find out specific subclades of the virus would perhaps tie that down to specific groups or regions, but evidence tends to indicate that the virus came in with the illegal children and was distributed with them. Occam's Razor, and all that...
You cannot make even a correlation unless you know the incidence of the virus in Latin America.
And then, to get evidence of origins, you need sequence data, preferably from each case. Then the phylogenetic trees can be built. With enough data, the phylogeny of the virus will reveal the path of its spread across the US.
I do not have the time to look into this, since although Ebola has fallen mostly out of the news (which is a *huge* relief), I am still very busy with it. I would love to be busy with other diseases.