Cornell University researchers have designed a model for a potential outbreak of zombie infection.
Using data from the 2010 U.S. census and the SIR model, an epidemiological tool that can project the progress of actual infectious diseases, the scientists created "large-scale exact stochastic dynamical simulation" of a such an outbreak. Their findings were to be presented Thursday to the august American Physical Society.
The interactive map shows how the zombie infection can spread. You can adjust several parameters for your apocalypse scenario. In the map shown, I began the outbreak in the most obvious place, Atlanta. In this scenario, zombies only kill one out of every four persons they bite, and it takes a zombie 18 minutes to walk a mile. Yet in only 48 hours, they’ve spread the infection over a huge part of the South. If you begin a scenario, you should leave it running for as long as it takes to determine the safest geographical area to hide. -via Metafilter
Imagine if, instead of merely getting sick, they got sick AND they turned savage and attacked their family and neighbors. I suspect that version of Ebola wouldn't last long, no matter what part of the world it starts in, as the infected wouldn't be treated like sick people as they are now, they'd be slaughtered.
And if the dead rose up from the grave and attacked again, they'd be slaughtered then burned. There'd be no patients being treated as long as there was no cure short of death, just pyres for the dead, and stories passed on from parent to child over the years of villages that had a small handful of cases that were swiftly killed and burned when the virus reared it's head.
That would be a good way to bypass most of that stuff I mentioned. Only, that wouldn't really be a zombie plague, would it?
Imagine watching a zombie movie where a guy who's been infected just goes about their lives for 8 years before going mad, biting two people, and being shot by the local cops. Along the way he may have infected maybe 2 people per year. Remember, this isn't the flu, only saliva or blood contact. Without patients going mad and biting folks every which way, the spread is greatly diminished. I feel a reasonable estimate for people just living their lives normally would be 2 people per year per person, so only 511 cases in 8 years.
Now that patient zero has gone mad and bitten people, the CDC gets involved to figure out why an otherwise normal person would do that. They suspect a new rabies strain or some such, and find our Z virus. Then, over the next few years, they track down at least half of those infected, and stop dozens more after they shift to the madness stage, stopping the spread even more. Within a dozen years, the infections are down to a manageable level, and a vaccine is being mass produced. Within 20 years, the new Z virus is contained in a similar manner to Small Pox.
Not a very exciting movie unless we fast forward through all the years where the people just go about their lives, and focus on the investigation of patient-to-patient spread of the virus and the slow, deliberate creation of a vaccine. Slow and deliberate because, let's face it, this virus spreads very slowly, so there's no hurry. Seems more like a medical drama than a zombie plague movie.
By making the virus incubate for a long period, we take out the primary fear of a zombie plague, the rapid drop to madness and biting to spread the disease further. It's scary if your buddy gets bitten and he might turn on you in the next few minutes or at best hours and you need to decide if you'll shoot them now or wait till they turn. It's not scary if your buddy is bitten and they go to a hospital to get a prescription for an antiviral drug that'll keep them fine for another 30 years while the virus sleeps. Or, if there's no cure or treatment, you can have the sad-but-still-not-scary ending where your buddy goes into quarantine and you can't see them ever again.
I suspect there's a reason why we haven't ever seen a Zombie flick where the virus has a slow incubation (not that I can recall, anyway), and almost never see how the Zombie plague gets started. The slow virus just doesn't get anywhere fast enough to be a threat, and even a fast virus can be stopped pretty quickly by rather mundane means, so the majority of films skip to the "some time ago the virus started and quickly swept through the world, now the survivors are fighting just to continue surviving" part.
Any of those things by themselves would help slow the spread. All of them together would likely stop it in its tracks before it got much out of one city, no matter where it starts in the US. In a third world country I could see it spreading slightly faster than in a first world country, but even then you have citizen militias and such that will stamp that *$@$ out as fast as it starts in even the most rural villages.
Almost any starting point I can imagine that starts with a zombie or two ends with a group of frightened people beating the unlife out of that thing with anything at hand (shovels, sticks, w/e) until there's no more threat. Even if we suppose 90% of people run in fear or freeze, the 10% will fight back and stop it with brooms and mops if necessary.
The one scenario I can come up with where most of those things I mentioned are made less effective is a terrorist-style mass-seeding of the virus at hundreds or thousands of geologically separate locations across the globe simultaneously. Make every country deal with a ton of separate outbreaks simultaneously and maybe the virus would have a chance to get a foothold somewhere before it got stamped out. Even then, each area would be dealt with eventually, so that the worst case scenario might get 50% of the population before it was stopped.
Honestly, the mobile game Plague Inc. does a better job of simulating a zombie apocalypse with their zombie virus DLC, and that's with the virus being controlled by a vindictive god who's specifically trying to infect everyone and can tactically react to whatever the world tries to do to stop it. And with all of that in it's favor, the infection is typically stopped rather quickly if the god in control doesn't do things just right.