SPOILER: So how did the Zombie Infection start?

[Extinction555]

The guy in the lifeguard house bathroom tells you "Its started by aliens"

"I heard this scourge came from outta space....came down on a goddamn meteor"
Lol hate that saying...but nah that's just his dumb butt opinion =P the scientists had something to do with it, and where did the natives get the infection if what Yig says is true?

[X-III]

I thought it was started by the guy who escapes with you on the chopper at the end. He's got a beard so he's obviously the bad guy.

I think it was a mix of this and the lab, the prison was a prison for and full of terrorist.
If you notice the guy who fly's the helicopter is in an orange jump suit which means he is one. I think it was an elaborate plan set up by him. He payed the lab to make a Bio weapon then played the part of the lackey to a terrorist prison gang while he watch his weapon rip through the island on an "accidental" test run.
And the natives are just being natives and thinking that it was a gift of immortality from their god or something.

That or I could be thinking too much into it...

[hunterxkx]

Charon was telling the scientists to make a virus for him to take with him on the chopper. Ryder thought it was the vacciene, but it just increased the virus. So the scientists+Charon=Zombies. Or...... IT WAS CHAMPAGNE!

[MrCostari]

Someone explained this to me.
Let me find it.

EDIT:

The virus origanlly must have came from Kuru, a type of prion that comes from the protein from our brains(gross.), So tribes that practice Cannabilism got this prion when they ate the brains of their victims, and sometimes the symptoms took years to show up, or it wouln't show up at all, but Kuru caused the person to slow lose their ability to walk straight, and in severe cases to become crazy. So in dead island they based the virus off of kuru but, more mutated and severe. So Ope's tribe ate brains of other people and contrated the virus, but then the virus became more mutated thanks to the scientists wanting to research more on Kuru, and created the zombies. Does it make sense now?

Here you are
Seems correct, right?

[ReznovKilledYOU]

Go beat the Ryder White Campaign then you'll know for sure xD

[MrCostari]

Go beat the Ryder White Campaign then you'll know for sure xD

Or just watch a playthrough Free

[ReznovKilledYOU]

Or just watch a playthrough Free

That's no fun though , You need the SATISFACTION of blowing up zombie heads.

[sartex]

That's no fun though , You need the SATISFACTION of blowing up zombie heads.

Ryde White campaign is hard and you can't play multiplayer, so the satisfaction of killing zombies is boring when they just run at u every second and u kill them all alone... i hate singleplayer.

[ReznovKilledYOU]

Ryde White campaign is hard and you can't play multiplayer, so the satisfaction of killing zombies is boring when they just run at u every second and u kill them all alone... i hate singleplayer.

I enjoy it :3

[CowardlyDawg]

If it all started at the lab wouldn't all the sicentists be dead? And what about the expirment on whoever they used, i thought scientists were smart so they would have thought to contain it... Ah well i don't know.