I think it's obvious that Asian countries will be the source of most epidemics because that's where most of the world lives.
I wouldn't be surprised if the next major epidemic comes from India, as that's the most populous country (though Indian's relatively large percentage of vegetarians and selective meat eaters should help prevent common infection patterns).
The Spanish flu (misleadingly named as it was first recorded in Kansas and only later reported in Europe) is kind of an outlier here, as was the Mexican swine flu.
What all this tells me is that if you study history you'll notice interesting patterns.
1. https://sv.wikipedia.org/wiki/Hongkonginfluensan