Cabin Fever (film)/WMG

These are Wild Mass Guesses regarding the Cabin Fever films.

The disease that the protagonists are infected with is not necrotizing fasciitis.
... Or any other mundane flesh-eating disease. It's a manifestation of Zalgo. Which means...

Winston is a (possibly unknowing) pawn of Zalgo.
Nearly everything he does in both movies only spreads the virus further. Based on his token efforts to track down the contamination in the second movie, he might not even realize that this is his entire purpose.

The second movie takes place in the Happy Tree Friends universe.
Seriously, it's too over-the-top not to.