Swamp Fever

Swamp Fever is a new campaign which takes place in a "swampy" location in Left 4 Dead 2, after evacuating from Savannah the Survivors will reach this swamp and escape from it in a boat familiar to the one in Death Toll, it is believed to be the third (most likely) or fourth campaign. It will be first revealed to the public in Comic Con 2009 through 23rd July to 26th July and will be fully playable to the public views in the Left 4 Dead Demo which will take place near November 2009. It seems as though it's a showcase for the AI Director's new, more in-depth level controls—such as the weather, and the new water system which slows the Survivors down and does not allow them to run.

Swamp Fever is also the only campaign that will contain the new uncommon Mud men infected, which are hard to spot, and extremely agile compared to the other common Infected.

Trivia

 * Swamp fever is a term given to a number of diseases that are acquired in wet, swampy environments.
 * Unlike The Parish, Swamp Fever ends its finale the same way all the other Left 4 Dead campaigns does -- that is, calling a rescue and waiting until arrival.
 * Some of the walls in a shanty house found in Swamp Fever can be broken off with weapon damage.
 * Swamp Fever was the very first campaign to reveal the Spitter in gameplay videos.
 * In the video of this level you can see a paratrooper hanging from their chute. an OXM article says that they are randomly located on the level by means of the Director, and will signify item drops underneath.
 * It has been seen in the game footages by GameSpy that the Survivors can find in the region of Swamp Fever the Weapons in Left 4 Dead the vanilla, such at the M16A3 assault rifle and M4 semi-automatic shotgun.