Cabin Fever: Patient Zero (2014)

At a secluded island laboratory run by the medical organisation CPEC, Dr. Edwards and fellow researchers Camila and Bridgett studies Mr. Porter, carrier of a deadly flesh-eating virus. Porter is asymptomatic and shows no signs of necrosis. For two months, Porter asks to see his wife Christina, his request is continually denied.

Marcus prepares to marry wealthy heiress Kate Arias in the Dominican Republic. Marcus's best friend Dobbs, his brother Josh, and Josh's girlfriend Penny charter a boat and take Mark to a supposedly unpopulated island for a bachelor party. On the way, Penny, Marcus's former flame, attempts to seduce him but is rebuffed.

Porter briefly warns a sympathetic Camila that he is dangerous. He attacks and infects Jorge, one of the researchers. Later, an outbreak occurs in the lab and Bridgett becomes infected.

Josh and Penny go snorkeling and see the decomposing carcasses of sea animals littering the ocean floor. When they return to camp, Josh and Penny discover strange rashes on their skin. While Josh performs oral sex on her, Penny begins spitting up large amounts of blood and her flesh starts melting. Josh radios for help and a voice claiming to be Dr. Edwards provides him with instructions.

Realizing that they need help but are stranded, Marcus and Dobbs search the island and find a bunker. Inside, the two friends discover research related to the virus. They also find mutated men who attempt to kill them. The two get away, but Dobbs becomes infected.

The bunker turns out to be connected to Dr. Edwards’ laboratory. Josh reunites with Marcus and Dobbs and they find the researchers. After formulating a plan for extraction, Bridgett and Josh split off to gather Penny and wait for the boat on the beach. Dobbs and Edwards also go on their own while Porter, Camila, and Marcus initiate the laboratory's self-destruct sequence.

Bridgett kills Josh and makes for the beach. Penny sees Bridgett trying to steal the dinghy and the two infected women fight to the death, dismembering each other in the process. Penny kills Bridgett, but succumbs to her illness and dies on the shore. Edwards also manages to kill Dobbs and escape to the beach with a rifle.

After rigging the lab to explode, Porter, Camila, and Marcus discover Dobbs’ and Josh's bodies and confront Dr. Edwards, who prepares to shoot Marcus. Porter, having been informed by Camila that his wife has been dead the entire time and Edwards has been lying to him, shoots and kills Edwards. Porter, Camila, and Marcus escape when the boat arrives.

On the boat, Porter gives Camila and Marcus each a bottled water to drink. Shortly thereafter, Camila and Marcus hear gun shots. They discover that Porter infected their water by injecting his blood into the bottles with a syringe before killing the boat captain and escaping in the dinghy. Camila and Marcus begin showing signs of infection.

Flashbacks reveal that it was Porter who lead Josh and the others to the bunker, using a radio he stole from Jorge to impersonate Edwards. Porter also infected a mouse, which led to the initial outbreak. The film ends with Porter heading to the mainland and the implication that he plans to spread the infection to the world.