Superbug

The Superbug is a 5th, purple disease with 24 cubes. When infecting the first 9 cities, the 1st, 4th and 7th cities get a purple cube in place of 1 of their cubes. Put 1 Superbug Infection card in the Infection Discard Pile and 1 on top of the Infection Deck, and 1 Superbug Bonus card in each Player card pile with its Epidemic. Whenever an Infection, Epidemic or Emergency Event hits a city with purple cubes, add 1 purple cube as well, even if its own disease is eradicated (with 3 already there, a purple outbreak instead); Treat Disease never removes purple. Quarantines are required.