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The Zombies you see in Left 4 Dead 1-2 are infected with a rabes-like disease that makes them very destructive and have a desire to infect everything that is healthy. The zombies have already found out that you (The Survivors) have an immunity to the disease that they carry, so they decide to kill you instead.

This disease apparently randomly came into action on the Earth and since then has infected over half of the world's population.

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14y ago
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12y ago

my gamertag for xbox live is Xxvictor619xX add me i play skate 3 and mw2 the infection started when a deadly chemical was released and infected most of the worlds population. the people did not know they were infected until they turned cold and died. the special infected did not start of like that. they were normal infected but evolved. beive it or not the boomer was actually skinny.the survivers cannot catch the infection as they are immune so the zombies kill em. But if you are infected your brain will go out of control and you do not know what is going on. the infection is a bit like rabies because you will go mad and infect anything you see!

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Q: How did the infection start in left 4 dead?
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Related questions

What started left 4 dead infection?

Rumor has it that a military experiment (As usual) started the infection.

Is left 4 dead real?

dont think so theres no such infection lol

How do you unlock the sacrifice in left 4 dead 2?

You don't, all campaigns are playable when you start Left 4 Dead 2.

What is the best infection game type for Halo 3?

Left 4 Dead, or Zombie House.

Is left 4 dead 3 coming out?

No, Left 4 Dead 3 is not coming out. There is only Left 4 Dead and Left 4 Dead 2. Both fun games.

Will left 4 dead work as a game for hl2 mods?

No, left 4 dead will only work for left 4 dead mods.

Can You Die In Left 4 Dead?

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Is there going to be a left 4 dead 4?

They (Valve and Havok) haven't announced a left 4 Dead 4, but they have announced a Left 4 Dead 3 coming out in 2011.

Is there a haggard in left 4 dead?

Not Left 4 Dead 1 or 2, but Valve and Havok announced the Haggard in Left 4 Dead 3.

How do you get the passing on left 4 dead 1?

You can't get The Passing on Left 4 Dead 1. It is only a DLC for Left 4 Dead 2.

What will appear in Left 4 Dead 3?

This is what was announced to appear in Left 4 Dead 3 by ValveINFECTEDBoomerWitchTankHunterJockeySpitterChargerSmokerNew!!! Infected DogsNew!!! StalkerNew!!! HeaterNew!!! TickSURVIVORSFrancis (Left 4 Dead)Bill (Left 4 Dead)Coach (Left 4 Dead 2)Ellis (Left 4 Dead 2)Louis (Left 4 Dead)Nick (Left 4 Dead 2)Zoey (Left 4 Dead)Rochelle (Left 4 Dead 2)New!!! LindsayNew!!! CandaceNew!!! JohnNew!!! MarcusCAMPAIGNS (from begining to end)New!!! Wrong Turn (4 Chapters)New!!! The Flashback* (5 Chapters)New!!! Last Ride (5 Chapters)New!!! Death Row (6 Chapters)New!!! Ticket Rush (6 Chapters)New!!! Mt. Saint HELLen's (8 Chapters)* - The Flashback campaign isn't really a campaign but missions in a flashback form scattered thorughout the game, explaining how the infection started up to this point.And in the flashback missions you are givin the choice to play as a past character from the first 2 games, or the new characters.

Is left 4 dead a good game?

Left 4 Dead is quite a good game if you like shooting zombies in an online mmo style. But, if you already have left 4 dead, you should get left 4 dead 2.