Survivor Strain

It's been two years since the so-called first wave, where hordes of infected got everything in their path. During this time, countries fought with all they had in order to stop it. Many succeeded, and many were completely lost. You were just a tourist caught during those events.
The story begins two years after the first wave in the last remaining country of South America, but for how long will this last? Will you be ready? What kind of leader will you become? How will you handle your enemies? Will you just eliminate them? Will you intimidate them to the point of fearing you? Or will you try to find a peaceful way?