Cabin Fever ending explained (spoilers)

[riley]

All of the kids die, and the disease was passed through the water. Some kids use the water to make lemonade and sell it to the townspeople, thus spreading the disease throughout the town.

[jesus]

Jeff, who has been hiding out and drinking in the woods, returns to the cabin. Initially crying after seeing the remains of his friends, he later becomes ecstatic upon realizing he is the only one who made it without being infected. As he raises his arms in victory, he is gunned down and killed by officer Winston. It also shows that Paul is already dead and we see Dennis behind him.