Cabin Fever 2: Spring Fever

"This time, it's spreading"

Cabin Fever 2: Spring Fever is a 2009 American horror film sequel to Cabin Fever, directed by Ti West.

A high school prom descends into sheer panic when a deadly flesh-eating virus spreads via a popular brand of bottled water.

Tropes used in Cabin Fever 2: Spring Fever include:

Alan Smithee: Ti West was so unhappy with the sequel that he asked to have his name removed from the film and replaced with Alan Smithee. Since he was not a member of the DGA his request was denied by the producers and he remains credited as the film's director. West has since disowned the final product claiming that it is more a product of the producers and executives than that of his own.
Anguished Declaration of Love: John confesses his love to Cassie while he is pissed off and screaming at her about dating a douchebag.
Animated Credits Opening: Shows the spread of the virus through the water supply as a visible red taint. A corresponding animated credit sequence occurs at the end, showing the further spread of the virus and that the country is pretty much screwed.
Artifact Title: There's no cabin in Cabin Fever 2. Almost the entire film takes place in a high school.
Billing Displacement/Dead Star Walking: Rider Strong doesn't make it past the opening credits. He's still the top billed.
Blood From the Mouth: A bunch of people at the prom are drinking punch made primarily from waterborne necrotizing fasciitis, so while it's implausible that they all start projectile vomiting blood at the halfway mark, it's at least justified.
Blood-Splattered Innocents: Everyone at the prom after the infected punch kicks in and they start vomiting blood all over each other.
Bloody Hilarious: The guy driving the truck of bottled water into town, who appears to have a stoma, starts choking while eating at a diner. Borderline dramatic. He tears his shirt open to reveal much of his chest and side have been eaten away by the virus. It's horrifying. He continues choking as a waitress attempts to perform an exorcism on him, and suddenly starts spraying the place with blood squirting out of his stoma. Uh...
Death by Sex: The wisecracking best friend is treated to some oral sex. The girl who administers it has a cold sore...which turns out to be the beginning stages of the disease. The disease spreads to aforementioned friend in a seriously disturbing way.)
Downer Ending: Only one student survives the sudden quarantine of her high school as the virus continues to spread across the nation with no chance of stopping.
Fan Disservice: The stripper at the end. You may never have an erection again.
Fingore: The wisecracking best friend sees one of his fingernails coming loose as he is getting ready for prom. He sticks it back in with superglue.
Foreshadowing: The punch a girl mixes up with the contaminated water looks unusually like blood...and the "contamination" depicted in the animated titles sequence.
I Drank What?: Turned up to teabagging levels here. The punch that everyone is drinking at the prom is not only made with the contaminated bottled water, but it was also pissed in by an infected custodian. (It's complicated).
Inferred Holocaust: The ending animation shows a trucker drinking Down Home Spring Water. He pees in the bottle and throws it at some dumb kids in a convertible. The kids are heading to New Orleans for Mardi Gras.
Jerkass: Marc, who not only bashes an infected student's head in, but bashes Cassie in the head with a hammer and attempts to kill John.
Life or Limb Decision: After Our Intrepid Protagonist gets some infected blood on his hand, he tries to forestall his own infection by cutting off said hand with a chop saw, with Cassie's help. It doesn't work.
Made of Plasticine: At the beginning, Paul is in the late stages of the virus and tries to escape the woods, leaving bits of himself behind on the trees and underbrush. He runs out onto the road, is hit by a school bus, and explodes in a splash of red.
Nice Job Breaking It, Hero: When faceless government goons come in and start shooting everyone, you're supposed to cheer for the plucky survivors who escape, right? Except by surviving and escaping, they've essentially doomed the rest of the world to The Plague.
Prom Baby: Happens very gruesomely, wherein a random promgoer has an extremely messy birth in the school restroom after contracting the virus. There is blood everywhere, including a rather conspicuous trail leading to the trashcan, suggesting a stillbirth. The actual condition of the newborn is left as an exercise for the viewer.
Senseless Phagia: To their credit, the promgoers do remark that the punch tastes like piss...
Shout-Out:
- Carrie: Cassie spends the last third in a prom dress splashed liberally with blood.
- The Evil Dead: The hero cuts off his hand when it gets infected. It didn't involve a chainsaw, though - he used a chop saw in the shop class.
- One of the dance-scenes features the theme from Prom Night.
The Stinger: Daryl and Dane (the only two characters who are clearly not infected) are seen watching a movie at home, and one of them says "Prom blows!"
Sudden Sequel Death Syndrome: Played with. Paul is revealed to be still alive (albeit falling apart) at the beginning, only to get splashed across the front of a school bus five minutes in.
Two-Person Pool Party: The Plague is waterborne. Squick happens.
Willing Suspension of Disbelief: Let's just pretend that it's possible for the quirky female love interest to change her mind about going to prom, finding tickets, picking out and ordering a really nice prom dress, and getting her hair styled in time at the last second.
- As Phelous pointed out, it seems pretty weird that Liz would treat Alex with disdain and even mock him for asking her to go to the prom with him... when ten seconds earlier, she was quite willing to perform oral sex on him.

Phelous: So he got used...by getting his cock sucked? Seems a little backwards.

- In this case, it wasn't about performing a sex act on him specifically, it was more about using him as a tool to get back at her asshole of an ex-boyfriend. He didn't matter to her beyond that.