It is a paramyxovirus that infects both the lungs and the brain, causing hacking coughs and fever, a severe headache, followed by a seizure, brain hemorrhage and ultimately, death. With an unusual incubation period, MEV-1 kills an infected person in approximately four days after infection and within hours of the onset of symptoms. The virus is transmitted by fomites, meaning it is transferred primarily by touching objects infected by the virus' carriers. A chimeric virus, MEV-1 is a combination of a virus whose natural host is the domestic pig and a virus whose natural host is a species of fruit bat native to China.
MEV-1 originated in Hong Kong when a man driving a bulldozer accidentally knocked down a palm tree where bats were nesting. The bats became disturbed and flew away. One of the bats was carrying a deadly disease and it flew onto a banana plant. The bat ate a chunk of the banana and flew onto a pole, and over a pig pen. The bat accidentally dropped a chunk of the banana out of its mouth and into the pig pen, where a pig ate the banana, and became infected with the bat's disease, creating a Bat-Pig hybrid. The next day, a group of Chinese chefs collected the pigs and sold them to a casino. While the chefs cut up the pigs, one of the chefs butchered the diseased pig and smothered his hands in its blood, infecting him with MEV-1 virus. The chef smeared the blood on his apron and went over to shake hands with Beth Emhoff, infecting her with the disease.