Most of us probably don’t spend much of our time thinking about bats. We might see them flitting around from time to time in the growing darkness, or occasionally encounter one which strays, mistakenly into our house, but beyond that, bats don’t really make much of a dent in the collective consciousness of humans except as stereotypes in B list horror movies and around Halloween.
Yet, it turns out that bats have a much darker side than anyone ever suspected, and it is this dark side which means that it could be them, rather than some mad scientist hunched over his test-tubes and giggling maniacally, that triggers the zombie apocalypse. Well, okay, I’m taking things a bit too far there, but they could certainly trigger a worldwide pandemic which could bring civilisation crashing to its knees.
Why do I say this? Well, because it almost happened once already. How many of you remember the global panic triggered by the SARS outbreak in 2003? If not, here’s a quick reminder. SARS or Severe Acute Respiratory Syndrome sprang out of nowhere and spread rapidly from Hong Kong to 37 countries across its nine month reign of terror. It killed almost 800 people, but more frighteningly it had a death rate of almost 10% (so one in ten people infected ended up dead). It also went airborne and leapt easily from person to person, and it was only a prompt worldwide response which finally brought it under control. When scientists started looking into where it came from, it quickly became clear that it was a zoonotic disease (that is one which leapt to humans from another animal species), and eventually the source was traced back to bats.
Now, you might think that this was a one-off, but it is far from it. If you want another example of a disease outbreak which originated from bats you need look no further than the much feared Ebola virus. Here’s a true nightmare disease that in some forms is 100% fatal and that basically causes your insides to turn to liquid and pour out through every orifice in your body.
Then there’s MERS or Middle East Respiratory Syndrome. That’s a new disease which is doing the rounds at the moment, killing a large proportion of people it infects, although it doesn’t seem to have gone airborne yet. It, too, is thought to have come from bats (albeit via camels).
This is just the start. There’s also the Hendra Virus (killed two in Australia), the Australian Lyssa Virus (a relative of rabies), the Nipah Viruus (it killed 50% of the 229 people it infected) and possibly the Marburg virus (a cousin of Ebola). Thus, bats are often the prime suspect when an emergent virus suddenly appears out of nowhere to devastate human populations large and small. And of course, bats are also a regular source of that old favourite of zombie authors – Rabies, so maybe the title of this article isn’t quite as far-fetched as it might at first seem.
So far these would-be epidemics have flared up and then died, some burning more brightly than others, but there are likely to be many other viruses out there lurking in bats, ready to jump to humans, and we never know when one of these viruses might have the killer combination of being highly contagious, kill a high proportion of those it infects and have airborne transmission from person to person and the luck to make it into our inter-connected system of flights and airports.
Normally, diseases have to trade-off virulence with the risk of extinction, because it they kill off too many of their hosts they risk killing themselves off too, but not zoonotic diseases. This is because they will continue to thrive in their primary hosts (non-human animals often referred to as the disease reservoir), so they can afford to wipe out any secondary hosts they leap into (like humans).
But, you may ask, why are bats so often the source of these outbreaks? First, and I must stress this, this is not because bats are some kind of disease-ridden pest. They are far from it. They probably carry no more diseases that humans do, it’s just that they are diseases we have not evolved to cope with. Similarly, they carry diseases which are no more inherently dangerous than those in many other animals, but they are ones we’ve never been exposed to before and this means we have no defences against them. In fact, the real risks comes from the actions of humans and not bats. Humans are impinging ever further into what was once pristine forests and wild lands all over the world and are destroying it at an ever-increasing rate. While many species perish, some bats can actually thrive quite well in or around human habitations. Indeed, many will quite happily roost in the buildings we construct, and this can bring humans and bats into ever-increasing levels of contact, an in ways which simply doesn’t happen with other animals.
Even then, many of the leaps of diseases from bats to humans come through accidental contamination, for example from farm animals eating fruit dropped by foraging bats, or getting infected from droppings of bats roosting over their heads in barns, and it is these animals which actually pass them onto humans. Occasionally, you get infections from direct contact. A few of these will be when someone, often a child, picks up a sick bat they find on the ground and are either scratched or bitten; more often, though, it comes from humans hunting and eating bats.
So how can we reduce the risk of diseases leaping from bats to humans? The answer is not in culling bats or trying to wipe them out, that would wrong on so many levels and it has been shown not to work. Instead, it is about modifying our behaviour and our buildings. We need to stop our continued destruction of untouched wilderness which brings us into contact with bats with new and frightening diseases in the first place. We also need to stop hunting and eating them for food. We need to make small changes to our farming methods to stop bats and farm animals coming into contact, and we need to educate people not to pick up sick or injured bats which they find on the ground. With these changes, we need not live in fear of bats, and instead we can live quite happily alongside them, and even share our homes with them.
So that’s it. while you might never suspect it to look at them, bats may carry within them the power to bring down humanity by infecting us with some terrifying new disease, but it is only our actions that will make it happen. This means that if there’s a zombie virus out there lurking in an unknown bat population in some as yet unexplored and unexploited rainforest, and it makes a leap into the human population, bringing the world as we know it to its knees, we will have no one to blame but ourselves.
For more information on bats and human diseases, click here.
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.