Many disease have a gap between the time a person is first exposed to it and the time they start showing symptoms. This is, technically, know as the latent period, and its length can vary quite considerably from disease to disease, and more importantly so can the ability of one person to infect others during it. With certain diseases, such as HIV, people can pass the infection on to someone else during this latent period, making it much harder to control. This is because the person themselves might not even know that they are carrying the disease and may fail to take measures to reduce the risk of passing it on. What, you may be thinking, does this have to do with zombies?
Well, the existence of a latent period, where a person is able to pass on the disease while appearing to be completely healthy, within a zombie-causing disease would have some dramatic implications for how it would spread and how it could be controlled. With zombie diseases, and here I’m talking of something which turns people into ravenous, flesh-hungry and violent killers, we would all instinctively know to keep away from the slobbering maniac with the crazed look in his dead eyes that’s trying to rip us limb from limb. However, what about the apparently healthy person who you meet while out foraging? With no latent period, you could pretty much assume that they’re okay and you could welcome them into your safe house or let them join up with your jolly band of survivors with little or no risk. If, however, there’s a latent period, this simple act of human kindness could be exceedingly dangerous. This is because you’d never know if they might be infected, and just not showing symptoms yet, with the risk that they will turn in the night and attack you without warning. These are The Carriers, and they’re the invisible threat in any zombie apocalypse.
The mere possibility of carriers means that you could never trust any new people you meet not to be infected, and just not showing symptoms. You could try asking them, but there’s a good chance they’d lie, or they might not even know they’re infected – believing that they’d been lucky and got away from an encounter with a zombie without picking up the disease. Instead, the best survival tactic would be to avoid mixing with strangers, and to drive any that come near you away before they get too close.
However, it wouldn’t just be strangers you’d have to worry about. Any time you were separated from others in your group, there’d be a chance that someone might become infected without realising it, or rather failing to mention that this might be a possibility because of how everyone else would respond. This means that every foraging trip, every scavenging run, every encounter with zombies would create the potential for someone to pick up the disease and return to your safe area, bringing it through all your carefully crafted defences.
Carriers mean that you could never really trust anyone and there’d always be the risk that someone will turn in the night, creating havoc as they run amok within your compound, and, indeed, this might be the most common way that safe zones would become overrun. The possibility that people could be infectious during a latent period, passing the disease on to others, would only make carriers all the more dangerous. Imagine the zombie disease spreading silently throughout your group before anyone is even aware that there is a risk of infection. This isn’t the blood-splattered attack of the fully fledged zombie horde which everyone would recognise as a danger. Instead, this is the invisible creeping of a disease through a community, with no one being able to do anything to stop it until it’s too late.
Therefore, the possibility of carriers is something which always needs to be guarded against by survivors in any zombie apocalypse. So, how would you go about doing this? Well, the answer is very simple, and very old-fashioned: Quarantine. That’s right, you’d simply require anyone who might have been exposed to spend a period of time in quarantine – separated from the rest of the group until you know they are safe. Luckily, under most zombie apocalypse scenarios, any periods of latency are likely to be relatively short because the disease which causes it is likely to be so voracious. This means a simple over-night quarantine might be enough to minimise the risk from potential carriers. However, proper quarantine procedures would be an important strategy for the survival of any group during zombie apocalypse, and these would need to be initiated right from the start. This means that you’d need to have a certain level of paranoia, especially towards strangers because of the risks they might pose in terms of bringing the disease into your group.
Of course, zombie apocalypse scenarios are fictional, but the possibility of carriers, and their ability to silently spread a disease through a community is a real medical threat. In traditional societies, there was a natural distrust of strangers, and often this was driven by the risk that they might bring new diseases into a group. Even in modern western societies, the risk of carriers has long been recognised. Ships arriving at a new country still have to fly a yellow quarantine flag until they are cleared for entry. Of course, nowadays this is more associated with checking passports and the search for smuggled contraband, but it’s a reminder that it wasn’t so long ago that ships arriving from far off places were regarded as dangerous because of the possibility they might bring diseases, such as the plague, smallpox and yellow fever, with them as well as the goods they carried.
In the modern, overly connected world, carriers are even more dangerous than in the age of sail. We might check passengers at airports for weapons and bombs, but people are rarely stopped to check whether they might be carrying a deadly disease. This allows older diseases, such as flu, and newly emerged ones, such as SARS, to be spread throughout the world within days or weeks, and before anyone really realises there’s a problem which needs to be dealt with. Air travel might be seen as a modern staple, but because of the existence of carriers, it actually makes us ever more vulnerable to being caught by surprise by diseases which could bring us to our knees if we’re not very careful about exactly how we handle them. And all because of that little interval in the transmission cycle of diseases called the latent period.
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.