The security guard opens his own beer twice right before giving the cop a beer from his secret stash.
Near the beginning of the film the school is a 2-story older red brick building, but during the prom it is a single story contemporary tan brick building. Additionally, you will notice the hallways have red and blue stripes early in the film, while later they are a light green (this is due to the crew being forced to change locations during filming).
The first time Alex calls to convince John to go to prom, John hangs up the phone and his alarm clock reads 7:13. The next time Alex calls John reaches for his phone the clock reads 7:12.
In the original Cabin Fever (2002), the water company was named Down Home Spring Water. In this film, the name has been shortened to Down Home Water.
In the library, John looks at the medical book Alex was reading. The first page shown has the word "underlying" misspelled as "undrelying." The next page with text misspells the word "amputated" as "amuptated".
As Alex and Cassie are walking home from school you can see leaves on the ground, and it is fall ,when the movie takes place in spring.
During the amputation scene, the arm is cut off right at the infection sight; this would have been much further up the arm to ensure its effectiveness. Also, Cassie holds his arm almost at the blisters, practically guaranteeing her getting infected.
The whole premise of the movie (a virus contaminating and being spread via water) is flawed. Viruses are only spread by person to person contact and will not survive outside a host or in a water supply. Bacteria and fungi, however may be able to survive and be spread from a contaminated water source.
The end credits attribute the song "Somebody Put Something in My Drink" to the Rawones, a misspelling of Ramones.
At the beginning, the cop says the bus hit a moose, while later we see trees with Spanish moss. Moose live in northern states and Canada while Spanish moss grows in the warmer southern states. The original story takes place in North Carolina, where there are no moose.