Everything You Ever Wanted to Know About Zombies (12 page)

Dr. Natalie Mtumbo of the World Health Organization suggests that the living zombies are in many ways less realistic than their classic undead counterparts. She explains that a disease spreading instantly through the body goes against everything we know about the rules of pathology, and so the
notion of an extended incubation period makes more sense, even if it includes death.
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Echoing this point, Dr. Phil Luton of the United Kingdom’s Centre for Emergency Preparedness and Response asserts that infectious-disease transmission requires an incubation period during which the patient is asymptomatic:

It has to get into the body. Next it has to take over the body and reproduce itself. It then has to get out of the body again and spread to the next person. Normally for that process to happen would be a minimum of two to three days.
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In 2005, the United States Centers for Disease Control and Prevention set up a network of training institutes across the country designed to strengthen the nation’s readiness for catastrophic public-health disasters. On condition of anonymity, a senior researcher at one such facility discussed several zombie doomsday scenarios, noting that the impact of infectious disease comes down to four measurable factors: susceptibility, exposure, infection, and recovery (or death), known as the SEIR model.

Assuming that the entire world is susceptible to the sickness, the researcher said that if zombieism is spread through a bite or some other close bodily contact, then you have a potential exposure problem, and the faster the infection spreads, the less likely it is to affect a large population.

He concludes that a lightning-quick virus is not only scientifically unrealistic, but it would draw too much attention to those infected in the early stages ever to represent a serious global threat. Instead, a zombie virus would likely need to have a long latency period, allowing it to infect a wide range of people across the planet before any symptoms appeared.

Unless the zombie sickness has a long latency period, experts agree that although off the charts in terms of creepiness, it would be considerably less concerning from a public-health standpoint than existing airborne pathogens that can spread easily across great distances.

If the infection does incubate more slowly and methodically, then there could be a troubling scenario at play with regard to its spread. Many blood-borne illnesses are transferred by mosquitoes. Malaria, for example, is almost exclusively passed from one carrier to another in this manner. But mosquitoes do not feed on dead animals or people, suggesting that zombies would not be part of their diet.

Mosquitoes use various cues to find food, but above all, they are olfactory creatures. Breath and body vapors draw them to their animal hosts, as does body temperature.
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Therefore, it stands to reason that a cold, rotting zombie would look nothing like a warm, living, breathing human to a mosquito.

However, a newly infected person who is still alive and kicking may be able to spread the infection before he even shows any signs of being sick. If that were the case, and if the zombie incubation period is as long as days or weeks,
then entire populations could be infected before anyone even knows there’s a problem.

Even once a person realizes that he’s sick, a real danger exists that the infection will be hidden from other survivors. Most zombie movies feature at least one infected character who hides his worsening condition from the rest of the group. He gets bitten on the arm and then simply puts a long-sleeved shirt on, pretending nothing ever happened. Filmmakers use this device to heighten drama and drive action, but in a real zombie outbreak, failure to identify and isolate the sick could mean certain death. And you can bet many infected won’t be eager to announce their new death sentence to the world.

The zombie life span is a key element of survival research, because if an accurate timeline can be established, starting with reanimation and ending with the final stages of decomposition, then strategies and expectations can be adjusted accordingly, resulting in millions of lives saved.

First, it’s important to note that by human physiological standards, zombies are dead. They are believed to have no heartbeat, their blood is cold, and their tissue is in a state of decay. So it stands to reason that by looking at the specifics of human decomposition, we can come closer to the truth about how long the modern zombie can function before rotting back into the earth.

The human corpse goes through several distinct stages of decay, including fresh, bloat, and putrefaction. In her 2004
New York Times
bestseller,
Stiff
, Mary Roach clearly breaks down this progression, noting that a hallmark of fresh-stage decay is a process called autolysis, or self-digestion. Roach
goes on to explain that all of the body’s internal organs liquefy in the fresh stage, including the brain.

In fact, because the brain is so soft and so close to hungry bacteria in the mouth, it is one of the first organs to go. By the second stage of decomposition, bloat, the brain has already been turned into a worthless puddle of mush, unable to keep from leaking out of the nasal cavity, much less control the actions of a bloodthirsty zombie. Therefore, it seems likely that a zombie’s life span lasts as long as the fresh stage of decomposition and not one moment longer.

Dr. Peter Cummings is a forensic pathologist and medical examiner at the Massachusetts Office of the Chief Medical Examiner and author of
The Neuropathology of Zombies.
His research suggests that the rate of decay could be significantly slowed in the undead, resulting in a life span that doesn’t last weeks or months but years or even decades:

I think they may be rotting at a much slower pace, like the foot of a diabetic. Their feet rot and toes fall off, but it happens over time. I also think that by having some basic metabolism, and some electrical stimulation to the muscles, they can decompose much slower.

If the undead do rot at a much slower pace than their human counterparts, zombie blood itself could act as a preservative. Embalming fluid makes the body’s cellular proteins toxic, so they can’t act as a nutrient source for invading bacteria. If the body fluids in a zombie are toxic, as is widely believed, it is possible that the system acts in a similar fashion to embalming fluid, thus slowing down decomposition considerably.

No matter what the process, it’s highly unlikely that zombies survive indefinitely. If nothing else, exposure to the elements over time would break down the undead body from the
outside in. Flesh would eventually wear away, and bone would become brittle and prone to breakage.

But if zombies don’t decay from the inside out as dead humans do, if they are not susceptible to the same hungry bacteria that turn our dead organs into mush in just a matter of days, then the critical window of survival may be much longer than anyone previously thought.

A 2009 sleep experiment from the University of Chicago proved that after thirty days of total sleep deprivation, a seemingly healthy rat will drop dead. In fact, all complex animated creatures—humans, rats, sheep, cockroaches—need some form of regular sleep cycle to stay alive.

These findings suggest that zombies may be able to slow their cellular breakdown by mimicking the survival techniques of the living. However, this doesn’t necessarily mean a traditional, tucked-in-bed, eight-hour recharge for our undead friends.

Think of it as the standby mode on your computer. The machine hasn’t shut down completely but is in a holding pattern, allowing it to last longer and run more efficiently when booted back up. Many insects and fish species act similarly, and so, too, may zombies. This would explain why they are often seen to be hardly moving at all when not in pursuit of prey.

Biologist Michael Harris suggests that zombies may be exhibiting a form of reduced metabolic state distinct from sleep, called mammalian torpor:

Torpor is a part of hibernation which, when exhibited by small mammals, leads to much reduced metabolism and reduced responsiveness. When exhibited by large
mammals the result is reduced metabolism and increased longevity, but with maintained responsiveness.

So the next time you spot a zombie milling about aimlessly, don’t just assume it’s too stupid or slow to do anything else. Maybe it’s just recharging so it can be refreshed and ready when the next tasty meal happens by.

If a person infected with zombie pathogens shows no sign of illness for an extended period of time, then there are many important questions to address. What are the rights of the infected? What liberties should be granted to people who have contracted the zombie illness but are not yet dead or dying? Who gets Bill’s stuff once we blow his head off?

If society does not collapse under the weight of a zombie pandemic, then the problem of what to do with thousands, or even millions, of friendly, everyday folk who just happen to have contracted a slow-acting, contagious disease that will eventually turn them into undead beasts may well become very real and very persistent. Do we shoot them on sight? Do we lock them up and throw away the key? What if they can live regular lives, with no sign of illness, for years? What if they can’t even pass on the contagion until the very latest stage of their own progression?

In the closest model for this potential reality, John Tayman’s bestselling work,
The Colony
, chronicles a dark chapter in Hawaiian history when thousands of lepers were forced to live on a remote island, separated from their families and
doomed to eke out their remaining days in deplorable conditions. Their sickness was ruled an illegal act, their rights were stripped, and they were treated as living corpses:

The patients were judged to be civilly dead, their spouses granted summary divorces, and their wills executed as if they were already in the grave.
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No matter how they were legally defined, the lepers were still alive when they were shipped away from the world. In fact, many lived years or decades in isolation, making them the first true example of the walking dead. It takes little imagination to see that the governmental and public response to the dreaded leprosy of old may be shockingly similar to that of the coming zombie pandemic.

The current malaria pandemic is a contemporary reminder of the challenges we will likely face when dealing with the rights of the infected. The World Health Organization estimates that there are as many as 500 million cases of malaria with more than 1 million resulting deaths each year. In fact, in Africa, a child dies from malaria every thirty seconds, and because the disease is transmitted by mosquito, it infects new victims without their knowing. Even though malaria patients are not themselves contagious, meaning that the disease cannot be transmitted directly from person to person, many face poor treatment upon diagnosis. They are locked away from society, stripped of their rights, and left to die in what
amounts to sealed prison cells. This does nothing to stop the spread of the disease but is simply an irrational reaction to the public’s fear and panic.

If a zombie pandemic hits with the same potency and spread as the current malaria crisis, there’s no telling to what lengths people will go to protect themselves from infection. Sure, little Jimmy down the street may just be showing the first signs of illness, and sure, you may know full well that he doesn’t even run the risk of developing full-blown zombieism for years to come, but don’t be surprised if you find yourself screaming for his head with the rest of the mob as you bash in his parents’ front door.

T
hink an undead virus isn’t possible? Researchers at the Herzberg Institute of Astrophysics in Canada claim that even though microbes are dead, they carry enough genetic information to allow new life to spring from their ashes. Team lead astronomer Paul Wesson even asserts that all life on earth may have originated from dead alien viruses that reanimated after reaching our planet:

The vast majority of organisms reach a new home in the Milky Way in a technically dead state. Resurrection may, however, be possible.
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Wesson’s hypothesis is highly speculative because we know so little about the true origins of life on earth. Nonetheless, if reanimated creatures are at the root of human civilization, it could be argued that the coming zombie plague is not only possible but likely. What’s more, we may already have the sickness inside our very DNA.