Zombie CSU (25 page)
Many of my experts came to the same conclusion, that prions would be a likely culprit in this kind of crisis.
Prions are very nasty little pathogens believed to be the driving force behind a variety of neurodegenerative diseases called transmissible spongiform encephalopathies (TSEs). They’re proteinaceous infectious microscopic particles, meaning that they are proteins similar in some ways to a virus, but prions have no nucleic acid. These diseases slowly attack brain tissue, often leaving spongelike holes (hence
spongiform
).
Mad cow disease (
bovine spongiform encephalopathy
) or BSE, is a prion disease affecting cattle. In 1986 an outbreak of BSE was diagnosed in England during which some 178,000 cows were believed to have been infected from a protein feed supplement that contained rendered remains of scrapie-infected sheep brains. Scrapie is a prion disease that affects sheep.
Prion diseases in humans can cause (among other things) loss of balance, disrupted coordination, blindness, dementia, sleep disorders, among other symptoms. All known prion diseases are invariably fatal.
The theory of disease-causing protein particles was established in 1982 by Stanley Prusiner, a neurologist at the University of California at San Francisco, who coined the term
prion,
5
and who went on to win the 1997 Nobel Prize in Physiology and Medicine for his discoveries.
There are three forms of TSEs affecting humans: sporadic, familial, and iatrogenic.
- Sporadic cases strike about one person per million; the cause is unknown, and no treatment for it exists. At the moment these account for close to 85 percent of all TSE cases.
- Familial cases, which account for 10 percent of TSEs, are passed down through bloodlines in ways not yet understood since inherited traits are genetic and prions have no DNA. There’s even a version called fatal familial insomnia (FFI), an ultrarare disease found in only a couple of dozen bloodlines worldwide, and in which the victim cannot ever fall asleep, not even when medicated. The victim becomes delusional and erratic, and lingers in a living hell of unending wakefulness until, months later, exhaustion and brain damage causes death.
- The remaining 5 percent are
iatrogenic
cases, which result from the accidental transmission of the causative agent via contaminated surgical equipment or as a result of cornea or dura mater transplants or the administration of human-derived pituitary growth hormones.
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The body’s immune system does not react to prion diseases the way it does to other diseases. The immune system doesn’t kick in and the disease spreads rapidly. Once it takes hold, there is no treatment.
And killing a prion is incredibly difficult. In labs, where growth hormones are cultivated from extracted pituitary glands, solvents of various kinds are used to purify the tissue; these solvents kill everything…except prions. Even formaldehyde won’t kill them. Radiation treatment and bombardment with ultraviolet light doesn’t kill them. Scientists have tried just about everything, including treating diseased brain tissues with all manner of chemicals including industrial detergent—and the prions endure. They don’t even die with the host organism. Bury a corpse with a prion disease and dig up the bones a century later…and the prions are still there. They are, after all, just proteins.
Art of the Dead—Chad Michael Ward
Rate of Infection
“I think zombie culture speaks to people on a primeval level and people can’t help but be drawn to it. Most zombie tales tend to be end of the world fables and that’s something that’s permeated our culure forever. I’ve always loved the slow, shuffling zombie—very apocalyptic, but the new fast versions cropping up in recent movies bring the fear to a whole new level. In the end, I think I’d have to go with fast.”
Prions and Cannibalism
One prion disease,
kuru
, found in the South Pacific, has a frightening link to eating human flesh. Among one tribe in the eastern highlands of Papua New Guinea it was the custom to show respect for deceased family members by eating them. Unfortunately this transmitted the disease from the organs and flesh of the dead to their living—but doomed—relatives. This practice has since been stopped and no further infections have occurred.
One of the many prion-related areas that has not yet been fully explored is the effect of radiation on prions. If it turns out that radiation in one of its many forms can mutate this disease, then we might be back with Romero’s space probe from
Night of the Living Dead
. So far, luckily, no evidence supports this.
Prion diseases in animals include:
Bovine spongiform encephalopathy
(BSE) in cattle (mad cow disease)- Chronic wasting disease
(CWD) in elk, moose, wapati, and mule deer - Exotic ungulate encephalopathy
(EUE) in nyala, oryx, and greater kudu - Feline spongiform encephalopathy
in cats - Scrapie
in sheep - Transmissible mink encephalopathy
(TME) in mink
Prion diseases in humans include:
- Alpers syndrome
, an autosomal recessive, mitochondrial DNA depletion disorder - Creutzfeldt-Jakob disease
(CJD) and its varieties: