I posted this as a response to another thread, but I thought it might bear its own entry under the variants so people can find it.

Here's simpler way of reducing the number of setup shuffles, which also mimicks the pattern that epidemic cards come up with the shuffle described in the rules.

With this method, you remove all the epidemic cards from the player deck and you add a new deck--let's call this deck a "turn" deck. The turn deck is composed of 5 cards, one of which indicates an epidemic (take A,2,3,4,5 from a deck of playing cards, and use the Ace as the epidemic marker).

During setup you shuffle the entire player deck (sans epidemics) and you shuffle the new turn deck.

At the end of a player's turn, instead of taking two player cards, you first turn over the top card of the turn deck. If this is an epidemic marker, then the player only draws one card from the player deck and there is an epidemic. If the card is not an epidemic marker, then the player draws two cards.

The turn deck is not reshuffled until all the cards are depleted from the turn deck. Then it is reshuffled.

Using the turn deck will exactly mimick the distribution pattern of the normal difficulty level for 2 or 4 players. Since there are 50 total cards in the player deck after you deal the starting cards to the players, there is one epidemic every 5 turns (if you divide the cards into 5 subpiles of 10 cards). For 3 players, this method should approximate the play fairly closely (there is only 49 cards in player deck after a total of 9 cards are dealt to the players, so the subpiles cannot be divided exactly evenly).

You can use a 4 card turn deck to play a "Heroic Plus" game (it is slightly harder than a Heroic game which averages an epidemic every 4.25 turns for 2 or 4 players and 4.17 turns for 3 player). You can get close to a "Heroic" by increasing the deck size of the turn deck to 5 cards for one or two times (i.e.: 4-4-5-4-4-4).

Using a 6 card turn deck simulates a 3 player "easy" difficulty game exactly and closely simulates a 2 or 4 player "easy" game (average 6.125 epidemics).

One advantage (or maybe disadvantage if you like the game harder) of the turn deck is that you can tell easily when the next epidemic might show up (or you can tell when it definitely won't show up). This is open information that can be tracked by the players (and should be tracked in heroic if you want to win more often), but with the turn deck it won't be necessary.

One thing the turn deck won't do is ever give you 2 epidemics in the same turn. If the rare "double epidemic" is desired in your game, some other mechanism will be needed.

Note that the turn deck might not reduce the number of shuffles(depending how long your game lasts), but it does remove the chore of dividing the player deck evenly into n parts. And the shuffling is not all at setup, but spread throughout the game, so setup time should be faster.