the symptoms were gradual but inexorable it began with headaches joint pain and tremors in the hands
and feet mild at first but growing steadily in intensity the victim's movements became
increasingly uncoordinated and clumsy their stance and gait unsteady soon they were unable to walk at
all racked by severe tremors and muscle spasms and then came the most alarming symptoms of all
his victims began bursting into tears or uncontrollable laughter without provocation
confusion delirium and paralysis followed until they were unable to move speak eat or make eye
contact finally 12 months after the onset of symptoms came the inevitable arrival of death
this was kuru a terrifying and incurable neurodegenerative disease that for nearly
100 years terrorized the foray people of papua new guinea for more than half a century the origins
of kuru remained a mystery until in the 1960s groundbreaking research revealed it to be caused
not by a bacterium virus parasite or even a fungus but by something far stranger in 1914 in the early
stages of the first world war the australian army invaded and occupied the imperial german colony
of new guinea what eventually became known as papua new guinea would remain under australian
control for another 70 years and over the following decades missionaries and colonial
patrol officers or coyops penetrated deeper and deeper into the interior in an attempt to bring
christianity and western legal administrative and medical practices to the indigenous peoples of the
island in the early 1950s reports began filtering back from colonial officials of a strange and
incurable disease plaguing the indigenous people of the eastern highlands including the four and
neighboring arwa yate and usurper known to the four is kuru from the word korea meaning to shake
or to tremble the disease caused a progressive loss of muscular control and invariably death
kuru was also known as naggy naggy or laughing sickness after the tendency of victims to burst
into spontaneous laughter in the latter stages of the disease thought to have originated somewhere
in the 1900s by the 1950s kuru had grown into a full-blown epidemic killing around 200 foray or
one percent of the population every year the first westerner to describe kuru as colonial patrol
officer asakari who observed in a 1951 report that the disease disproportionately affected foreign
women and children over the men the disease was also described by anthropologists ronald
and catherine burnt in 1952 and patrol officer john mcarthur in 1953. however all dismissed the
epidemic as purely a psychological phenomenon a form of mass hysteria deriving from forays beliefs
in witchcraft and spirit possession indeed the pharah themselves initially believed that kuru
was caused by malicious sorcerers from rival groups who would acquire parts of the victim's
body such as hair or nail clippings and combined with clothing leaves blood and other materials
form a kuru bundle the sorcerer would then shake the bundle daily until the telltale tremors of
kuru were induced in the intended victim however american virologist daniel gadgesack and physician
vincent zieger strongly doubted that kuru could be purely psychological writing to ronald burns that
our current opinion is that fatal kuru cannot by any stretch of the imagination be identified with
hysteria psychosis or any known psychologically induced illnesses the evidence for direct nervous
system damage is far too great in the strabismus drooping or closed eyes and pictures of advanced
neurological disease shown by the advanced cases consequently in 1957 giuseppe and ziges
launched the first proper scientific study of curry their analysis published in the medical
journal of australia suggested that kuru might be genetic in origin passed down along family lines
however confirmation of this hypothesis would require closer study of kinship among the foray
in 1961 medical researcher michael alpers and anthropologist shirley lindenbaum used a
research grant from the rockefeller foundation to travel to the eastern island of papua new
guinea to conduct a thorough anthropological and epidemiological study of the foray over the next
two years alpers and lindabaum discovered that kinship among the foray was not strictly based
on biological relatedness but rather a complex system of social association and bonding with
neighboring individuals curry they found spread mainly along kinship lines and not strictly
between biologically related individuals making it unlikely that it was transmitted genetically
epidemiological data further ruled out transmission by air insects or contaminated water
so just how was it transmitted the unexpected answer would stun the scientific community
and open a strange new chapter into the study of human disease kuru alpes and lindaban discovered
was spread through cannibalism at the time the foray people practiced a form of what is known as
mortuary cannibalism ritually consuming the bodies of deceased family members as a means of honoring
the dead and returning their spirit or life horse to the community bodies would be buried for
several days until they were infested with maggots before being exhumed and dismembered cooked and
eaten communally the maggots being served as a side dish and while the foray avoided the bodies
of those people who had died of dysentery leprosy and other diseases those who succumbed to kuru
were still regularly consumed the more alpers and lindabaum observed the more convinced they became
that this practice was at the heart of the kuru epidemic for example preparation of the bodies
was performed almost exclusively by women who were also far more likely to engage in cannibalism than
the men there were two main reasons for this first male foreign believed that eating human flesh
would weaken them in times of war second women's bodies were thought to be better able to tame the
absorbed spirits of the dead more telling still the brain the organ most affected by kuru was also
largely consumed by women and children while men when they did engage in cannibalism preferred to
eat the bodies of other men together these facts seem to explain why kuro affected predominantly
women and children with only around three percent of foreign men succumbing to the disease
yet despite this compelling evidence for kuru's origins and transmission route scientists still
did not know what actually caused the disease in order to find out in 1968 albers collected brain
sample tissues from the body of an eleven-year-old foray girl who had died of kuru and delivered them
to daniel gangesuk at the national institutes of health along with collaborator joe gibbs gadget
set ground up the samples and injected them into the brains of chimpanzees within two years the
apes began showing the telltale signs of kuru severe tremors gradual loss of muscular control
and cognitive function and finally death when gadjasay could gibbs or top seed the animal they
found that its brain particularly the cerebellum which controls muscular coordination was riddled
with millions of microscopic holes giving it the appearance of a sponge or swiss cheese under the
microscope the experiment not only confirmed that kuru was spread via infected tissue and
that it directly attacked the brain but was also an extremely rare instance of a disease jumping
from one species to another in a laboratory setting and the first known case of a contagious
neurodegenerative disorder but while this research would earn gadgetsek the nobel prize in physiology
and medicine in 1976 he was ultimately unable to isolate the actual pathogen responsible for curi
experiments after experiment ruled out bacteria viruses fungi and protists leaving the actual
causative agent a baffling mystery the mystery of curry would not be solved until the late 1970s
when gadjasek along with british researchers e.j field tikvah alper and john griffith noted
striking similarities between kuru and the ailment scrapey and kreutzfeld jacob disease or cjd scrapy
first described in the 18th century as a disease affecting mainly sheep and goats named for the
itching sensation that causes afflicted animals to scrape their skin raw on trees and fences while
cjd is a rare human neurodegenerative disorder first described in the 1920s like kuru both are
untreatable and invariably fatal in a series of groundbreaking experiments griffith demonstrated
that scrapey could be transmitted via infected brain tissue which had been completely sterilized
and that the causative agent whatever it was was resistant to destruction by heating ultraviolet
light and ionizing radiation this led griffith to a radical conclusion that these diseases
were caused not by conventional pathogens but something far stranger rogue misshapen proteins
called prions unlike bacteria proteus fungi or depending on which size of a particularly heated
scientific debate you happen to stand on viruses prions a contraction of proteinaceous infectious
particles are not actually alive rather they are proteins of the same types that make up the bodies
of healthy humans and animals however prions are the mr hides to the original protein's dr
jekyll a misshapen deformed variant incapable of performing its original biological function when
a prion enters the body it latches on to another normal version of the same protein causing it
to transform into the same mutated form as itself this in turn triggers a deadly chain
reaction gradually transforming and destroying the entirety of the host tissue though prion diseases
are typically acquired from other infected hosts they can occur spontaneously when normal proteins
mutate into a malignant form triggering the same transformational chain reaction indeed it is now
believed that kuru in new guinea originated sometime in the early 1900s when an unknown
individual spontaneously developed the disease and gradually spread through the foray population by
a mortuary cannibalism the sponge-like holes as a prions inflict in the victim's brain tissue what
give kuru cjd scrapy and other similar diseases their collective name transmissible spongiform
encephalopathy if that name sounds familiar it's because prions are also responsible for bovine
spongio form encephalopathy or bse better known as mad cow disease lycoru bsc is also spread through
cannibalism though a rather different sort in the 1980s and 1990s a massive outbreak of bse in the
uk was linked to the use of meat and bone meal or mbm in animal feed mbm is rendered from the
parts of slaughtered animals considered unfit for human consumption including blood bone hooves horn
skin and most relevant to the transmission of bse brain and nerve tissue the transmission of bse via
infected animal feed devastated the uk livestock sector triggering worldwide bans on british beef
killing hundreds of cows outright and resulted in 4 million animals being slaughtered and
incinerated in an attempt to contain the outbreak even more tragically 177 people contracted variant
cjd the human form of bse from eating contaminated beef with all of them invariably succumbing to the
disease in the wake of the outbreak the uk banned the use of mbm for feeding cows sheep goats and
other ruminant animals though it remains a common ingredient in pet food though their existence
had been theorized for over a decade prions were not isolated in the laboratory until 1982
by american researcher stanley prisoner of the university of california earning him the nobel
prize in 1997 for physiology and medicine this discovery of a brand new infectious
agent opened up a brand new field in the study of communicable diseases and led geneticists
to rethink certain assumptions regarding the transmission of structural information between
genes and proteins some scientists now also suspect that alzheimer's disease may be caused
by a type of prion opening exciting new avenues of research for the treatment of the disease which
afflicts up to 30 million people worldwide every year yet despite this new understanding
mystery still surrounded curry the first human prion disease to be positively identified even
before cannibalism was suspected as the cause of kuru the practice was strongly discouraged
by missionaries and colonial patrol officers by the 1960s when alpers and lindebon began
their groundbreaking study before it all but abandoned mortuary cannibalism however the
epidemic continued for decades with deaths between 1987 and 1995 averaging seven per
year it is now known that kuru has an extremely long latency period ranging anywhere between 3
and 50 years between infection and the onset of symptoms allowing cases to appear long after the
abandonment of cannibalism indeed the fact that nobody born after 1960 has ever contracted the
disease has served to confirm the link between guru and the practice of mortuary cannibalism
thankfully however there is reason to believe that after more than 100 years the kuro epidemic may at
last be over the last person to die of kuru was in 2009 and no new cases have been reported as
of 2010. even more encouragingly it appears as if the foray may have actually developed an immunity
to kuru shielding them from future outbreaks the 1996 study conducted by a team from the
university college london found a high prevalence of a gene mutation called g127 among the foray
which prevents malignant prions like kuru from infecting the brain genetic analysis
has further revealed that this mutation appeared as recently as 10 generations ago as john collinge
a researcher at university college's pre-owned unit remarked it's absolutely fascinating to see
darwinian principles at work here the community of people has developed their own biologically
unique response to a truly terrible epidemic the fact that this genetic evolution has happened in
a matter of decades is remarkable so for all of you aspiring hannibal actors out there the tragic
case of kuru provides yet one more reason why outside of extreme survival situations
cannibalism is really a good idea better to pair your fava beans and chianti with something
slightly less exotic so i really hope you found that video interesting if you did please do hit
that thumbs up button below don't forget to subscribe and as always thank you for watching