Many zombie-type stories start with an outbreak of a disease that either turns living people into violent maniacs (think of the rage virus in 28 Days Later), or converts them into the walking dead (as is the case in World War Z). These diseases are fictional, but there are real ones out there that are just as scary and that share many of the same traits as any zombie infection. They may get passed on through bites and frequently they’ll hack into your brain, gradually taking it over and, in some cases, making you do things that you wouldn’t normally do. In this article, I’m going to introduce you to three of these ‘zombie’ diseases. You might think these are obscure diseases only found in far-flung rain-forests but, depending on where in the world you live, you’re likely to find one, and possibly all three, can be caught within easy walking distance of your own home, or even inside it. This is something I can say with certainty from first-hand experience as I’m currently being treated for one of them.
So I’ll start with the one I currently have. This is Lyme Disease, named after a town in Connecticut and only discovered in the 1970s. This is an insidious little disease. It’s spread through tick bites (that’s how I picked it up), and often starts with classic flu-like symptoms and a rash that radiates slowly away from the bite site. It’s strange watching, as I have done for the last week, the rash spread over several days, as the infection works it’s way through your flesh (I can’t help but be reminded of a festering bite from a zombie whenever I look at the one currently spreading across my leg). Then the rash goes away and all seems fine. It’s only months, or sometimes years, later that the real problems kick in. This can be chronic fatigue, muscle weakness and paralysis, turning you into a shambling, groggy zombie. The strain you get in Europe also has a tendency to get into your brain, causing neurological problems. Luckily it’s easily treated, at least in the early stages, and a two-week course of antibiotics is enough to rid your body of the bacteria that cause it. Later stages are more difficult to treat, but it’s still treatable none the less.
The next disease I want to consider is rabies. Rabies is something that in western countries has pretty much been eliminated (although it is making a comeback in some places as wildlife re-invades our cities and homes), and we’ve forgotten quite what a horrific disease it is. The virus causes those infected with it to produce vast amounts of saliva, causing them to, quite literally, foam at the mouth. This is the disease’s cunning way of getting passed on because the saliva is full of the virus, ready to infect anyone the carrier bites. It also takes control of the brain, making the infected animal or person do things they wouldn’t normally do. This includes relentlessly attacking others with little or no fear. While there’s a vaccine for rabies, this will only work if it’s given before the infection reaches the brain and the victim starts showing symptoms. After that, death is almost a certainly, but only after the infected person has been sent mad, because there’s no treatment, and no cure. Because of it’s terrifying characteristics, including the way it takes over people’s brains, rabies has often been used as an agent to create zombie-like creatures (including my own book For Those In Peril On the Sea). However, real rabies differs from these fictional accounts in that it progresses ever so slowly, taking months, or years in some cases, to kill its victims, and there have been no known cases of human to human transmission.
You might think you’d be safe from animal-borne diseases in your own home, but there’s one we readily invite into our houses, or at least people with cats do. This is toxoplasmosis. At first, toxoplasmosis mightn’t seem like a zombie disease, but once you find out what it does, and why, you’ll see why I think it is. Toxoplasmosis is caused by a protozoan parasite. It’s main host is cats, either of the domestic or big variety, and it does them little harm. Why would it? It needs its cat host to be healthy so it can survive. However, the offspring are passed out in the cat’s faeces, and this is where humans can pick it up, especially when cleaning out litter trays. While it can cause serious problems to people with weakened immune systems, it’s most insidious effect comes in otherwise healthy people. In them, it can form cysts in the brain that will sit there, apparently doing nothing. These cysts are surprisingly common and can be found in ten percent or more of the human population. Experiments have shown that rodents infected with toxoplasmosis become fearless, even approaching cats rather than running away from them. If you think about this from the parasite’s point of view, fiddling with the rodent’s brain like this is the perfect way to ensure that it ends up back where it wants to be. That is inside a cat. Yet, there is evidence (equivocal I’ll admit, but it’s still interesting) that toxoplasmosis affects humans in a similar way, making them more reckless. Why would it do this? Well, if you think back a few hundred thousand years to a human on the plains of Africa, this would be the perfect behaviour to ensure someone was eaten by a big cat, so completing the circle of life (at least from the parasite’s point of view!).
So here we have three real diseases, each of which has elements of the fictional zombie diseases used in so many books and movies. Two are spread through bites, all will infest your brain if given have a chance and will change how you think and behave, and one (Rabies) turns you into something so similar to the zombie-type infected of 28 Days Later that it’s truly frightening. In fact, the only real difference between these real diseases and the fictitious ones is the rates at which they spread. Almost all are slow-acting, taking weeks, months or years to take over your brain, and none have the virulence of the fictional ones. But, just think what would happen if, for some reason, this were ever to change?
If you’re interested seeing a bit more on this subject, here’s some links to some follow-up videos:
This link shows how little fear a rat infected with toxoplasmosis has for cats (in this case going as far as attacking it!):
These two links are more about possible links between toxoplasmosis and zombie outbreaks:
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 print and as a Kindle ebook. Click here or visit www.forthoseinperil.net to find out more. To download a preview of the first three chapters, click here.
To read the Foreword Clarion Review of For Those In Peril On The Sea (where it scored five stars out of five) click here.