Well not quite.. but this game seems very topical in the current climes:

http://www.kongregate.com/games/DarkRealmStudios/pandemic-2

You play a virus, bacteria or parasite and your mission is to become the pandemic that exterminates humanity.
Choose your genetic traits and watch as the puny meatbags dies in their millions.

Stay relatively non-lethal till you spread enough to get a good foothold then start mutating to a more lethal form.

Having played this extensively I have concluded that I will be building my swine flu apocalypse bunker in Madagascar.

Madagascar is always the bastard one to get, helps if you start there or Africa…