Zombie Apocalypse Day 56

Ok I know I am behind the times here, but this zombie apocalypse is not limited to simple turning human beings into 1950′s horror icons.  This is about rampant, out of control diseases that were once only thought to be fantasies.   We now have the Bubonic Plague to worry about?!  How and why is this happening?  Are we experiments?  Is this due to the over prescription of Anti-biotics?  Is Mother Nature flexing her muscle?