It has recently been announced that two sequels to Cabin Fever are in the planning stages. We have details on the first film, including the director, plot, and sales art.
Titled Cabin Fever: Patient Zero, the film is set to "tell the origin of the flesh-eating virus that was unleashed in the 2002 original [film]. The new film follows the passengers of a cruise ship in the Caribbean that runs aground a research island. They must find a way to survive before the disease consumes them."
The script was written by Jake Wade Wall (The Hitcher remake) and Kaare Andrews is reportedly in final negotiations to direct the film. Cabin Fever producer Evan Astrowsky is on board once again, along with his Hypotenuse Pictures and Indomina Group. It's been mentioned that they have the plan is to produce a second film after this, titled Cabin Fever: Outbreak.
Thanks to Bloody Disgusting, we have the sales art for Patient Zero below and also confirmation that Adam and Deborah Marcus (Leatherface 3D) are working on the story for Cabin Fever: Outbreak. Here are the plot details for that project: "In this film a doctor and his family travel to a remote Caribbean island to investigate a minor flu outbreak, only to discover a vicious flesh-eating virus that threatens everyone on the island. The family is faced with responsibility to prevent a worldwide epidemic."