Those of you who have read my posts before will know that when it comes to the question of whether a real life zombie apocalypse could actually happen, I say yes, but not if it involves your traditional, re-animated corpses. Rather, I favour the premise of an infectious disease (whether natural or man-made) that turns living people into zombie-like killers. As I’ve explored in previous posts, there’s actually no scientific reason that such a thing couldn’t happen and there are plenty of diseases already out there that have to potential to take over the human brain.
In this post, I want to explore something slightly different. This is the question of whether animals can become zombies. Why is this important? Well, it all revolves around the idea of disease reservoirs. A disease reservoir is a population of animals where a disease can circulate outside of humans. Think, for example, of rodents for the plague, bats for the Ebola virus and many different animals for rabies (now there’s a real zombie disease for you!). For humans, diseases with animal reservoirs can have very different epidemiologies than diseases that are restricted to our own species. In particular, they’re much harder to eradicate and can suddenly flare up again somewhere new even when we think we’ve beaten it. Look at the Ebola virus. It circulates in other animals (the exact species involved aren’t known but many suspect fruit bats) and every now and then it leaps across to humans, killing tens or hundreds of people before melting away again only to strike reappear somewhere else a few years later. This is what makes it so hard to study and control, and so damned scary too.
So where does the zombie apocalypse fit into all this? Well, if a disease were to appear that was highly infectious and that caused people to act like zombies but was limited to humans, we’d have a chance of beating it using the traditional medical approaches of using isolation and containment to break the cycle of infection. I’m not saying it wouldn’t be hard, or that it wouldn’t involve a lot of hard choices that could mean a lot of lives being sacrificed, but it might at least be possible. It would also mean that if we can survive long enough, there’s a chance that the epidemic would burn itself out. After all, humans can’t last forever without eating and those infected with the disease are likely to starve to death once they’ve run out of fresh humans to feed on.
If, on the other hand, the zombie apocalypse were to be caused by a disease that has an animal reservoir, we’re well and truly screwed. This is because it would be so much harder to fight. We could contain an area from a human perspective but would we notice an infected mouse sneaking out? Or a bat? What happens if the reservoir included birds as well as mammals? We’d never be able to isolate any individual outbreak and we’d have them popping up all over the place. Birds as a reservoir of a zombie disease would be particularly scary since the sea would act as no barrier (there goes all my plans for how to survive when the zombie apocalypse comes!), allowing it to leap from continent to continent and reach even the most remote islands on the planet.
Animals infected with a zombie virus would also be much harder to protect ourselves from. Humans are big, we can see them coming and they’re relatively easy to keep out or kill. But what about rats? It is said that in many cities, you’re never more than a few feet from a rat and if we’re talking about a rodent disease reservoir here, then they could easily appear out of nowhere and bite you before you ever even knew they were there. If we look at rabies we can see this happening again and again, so there’s no reason to believe that the same couldn’t happen with a zombie disease. Again, think what would happen if it could infect birds and not just mammals. Fences and barricades wouldn’t be able to keep them out and we’d never be safe in our compounds or mountain hideaway or where ever we choose to make our last stand against the infected because death could come from the sky at any moment. You might think caves and underground chambers would be safe but what about bats? They’re perfectly at home there and remember they’re one of the most common sources of human rabies infections in many countries so they’re not as harmless as you might think.
So what does all this mean? It means that if we’re ever faced with a true zombie disease, after containing the initial outbreak (if we can), one of the most important things we’ll need to do is to determine is whether animals can get too, and how many different species can carry it. We could then amend our strategies depending on what we find. If the disease cannot cross the species barrier, we can, to some extent, breathe a sigh of relief. It will be difficult and it will be bloody but it will be beatable – even if all we can do is hole up somewhere and wait for the disease to burn itself out. If, however, animals can catch it as well and transmit it back to us, then we might as well give up there and then. Even if we can somehow get it under control in the human population, we will never really be free of it. There will always be the risk of it flaring up again and again whenever humans and infected animals meet and even if we survive the initial outbreak, we will never be safe again. It’s a depressing thought and it means that all we can do when the worst happens is hope for the best: that animals can’t become zombies too.
From the author of For Those In Peril On The Sea, a tale of post-apocalyptic survival in a world where zombie-like infected rule the land and all the last few human survivors can do is stay on their boats and try to survive. Now available in the UK, and available as an ebook and in print the US from the 21st March 2013. Click here or visit www.forthoseinperil.net to find out more.