There's something about a potential virus threat that's a whole lot scarier than a lunatic in a mask, or demons ascending from hell. The idea that a virus is invisible yet deadly, that there's no way for the general public to fight it, and that we could infect or be infected by our loved ones just by being near them is horrifying. The recent Ebola outbreak has brought with it a fresh fear with regards to the dangers of mutated viruses. With Ebola's terrifyingly visceral symptoms, its relatively fast spread, and high mortality rate, the virus acts as a shocking reminder that humanity is a lot more fragile than we might like to think. The idea of a seemingly unstoppable virus devastating the world is an idea that has long been explored by Hollywood, with mixed results. The classic zombie films generally rely on the idea of a mutated virus of some kind, while movies about the spread of a virus have become a 'disaster movie' sub-genre in their own right. This list takes a look at 10 of the deadliest movie viruses ever to be conceived on screen. From undead-turning pandemics to those more grounded in reality, each of these viruses make Ebola look insignificant in comparison.