The scenario played out in this movie was based on the Nipah Virus
. The first outbreak of this nasty disease was discovered in 1999 with Malaysian pig farmers.
Nipah is a zoonotic virus, (transmitted from animals to humans), it begins in the fruit bat, and the hypothesis is that pigs end up eating fruit chewed on by infected fruit bats. The pigs go to slaughter and enters the food chain.
There have been a total of 13 outbreaks of this virus, all in south Asia, since 1999. While the global pandemic depicted in the movie has not occurred, just about everything that happens in the flick is scientifically plausible, which makes the story so much more frightening.
The symptoms include anything from flu-like all the way up to encephalitis and coma. 20% of those that survive the virus have residual complications like personality changes and neurological defects.
Worse still, the fatality rate in south Asia has been from 40% to 75%, depending on medical and monitoring resources. 4 to 7 out of 10 people who contracted it, died.