KURU
KURU
TONY ASHBY
Professor Michael Alpers surrounded by the
artefacts of his extraordinary career.
The
Last Laughing Death
By Jo Chandler
November 13,
2012
November 13,
2012
After 55 years, the final
patrol for cases of the mysterious ‘laughing death’ in remote Papua New Guinea
has returned from the highlands. From this pursuit came Nobel-winning science,
clues to ‘mad cow’ and insights into Alzheimer’s disease. It also revealed a
little bit of cannibal hidden in us all.
It’s 50 years since Michael Alpers, a 28-year-old
medical graduate from Adelaide with a restless spirit and an urge “to do health
in a different kind of way”, hiked into the Papua New Guinea highlands looking
for the crucible of a devastating disease epidemic — and stumbled into the
crater of an uncharted volcano.
While he smartly sidestepped the sulphuric grumblings
of Mount Yelia, young Dr Alpers never really made it back from that trek,
succumbing en route to a mystery, a mission, and a culture. This month the
now-venerable professor’s long expedition reaches its conclusion: The last of
the corps of local foot-soldiers he trained over decades to track down and
document cases of kuru — the name the afflicted Fore people
gave to the tremors signalling inevitable and terrible death — are just winding
up their final routine surveillance patrols through the villages where the
disease once raged.
Today’s kuru reporters will emerge
from their last monthly trek through the mountains and negotiate the rough
track north to the provincial capital of Goroka — a four-hour trip, if the
route has not washed away in the latest downpour. When they have submitted
their final reports to the PNG Institute of Medical Research and collected
their last pay cheques, the file will be closed on an epic continuous
surveillance effort which began when the first documented reports of the
disease emerged in 1957. Along the way, its foot soldiers have navigated some
of the most arduous geographical, cultural and humanitarian landscapes imaginable.
Several of the surveyors are second-generation kuru sleuths
and bush medics, heirs to the stories and skills their fathers acquired in the
1960s when they accompanied Alpers and other pioneering investigators during
the height of the kuru scourge. Then the mysterious disease
was killing up to 200 people a year — mostly women and children — in the Purosa
Valley, in the remote Eastern Highlands. It very nearly wiped out the Fore.
Locals blamed powerful ritual sorcery for the curse; intrigued medical
scientists postulated a genetic cause, or maybe an environmental factor; and
patrol officers installed by the Australian administration suspected the Fore
tradition of eating their dead — an outlawed practice that had largely ended by
1960. They would all, to varying degrees, turn out to have part of the story.
Fore people recruited to “The Kuru Project”
worked as translators, guides, cultural advisors, nurses, autopsy assistants,
couriers, cooks, security guards, drivers, carriers and custodians of precious
human tissue destined for research laboratories in Melbourne, Washington and
London. They were instrumental in what is recognised as one of the greatest
discoveries in biomedical sciences of the 20th century.
Their involvement was critical to the collection of
field data from villages scattered through rugged, remote terrain; the
co-ordinated efforts of field workers and scientists ultimately garnered two
Nobel prizes (and contributed indirectly to a third). Their continuing surveys
have informed and shaped the public-health response to Europe’s “mad cow”
disease, particularly at its British epicentre, providing warning that a
substantial second wave of deaths is inevitable, and that dormant carriers of
the infection will long pose a threat to safe blood, organ and tissue supplies.
Their legacy also endures in the footnotes of emerging insights into
neurodegenerative diseases such as Alzheimer’s and Parkinson’s diseases.
“We had to climb mountains and cross fast-flowing
rivers,” one of their original ranks, Taka Gomea, recalled at a Royal Society
gathering on kuru in London five years ago. “When we
approached some villages they tried to chase us away, threatening us with their
bows and arrows. We would placate them by giving them salt and other small
presents.” En route by Dakota aircraft to one patrol site, Gomea recalled an
occasion when the cargo doors burst open. He clung to the co-pilot so he could
lean out and pull them shut. “I really wanted kuru to stop,”
said Gomea, who eventually became an orderly at a remote medical aid post.
“That’s why I was happy to work so hard.”
His wish was granted. There have been just eight kuru cases
this century — three in 2000, two in 2001, one each in ’03 and ’05, and the
last in 2009. In each case, it is believed the victim had incubated the disease
for an astonishing 50 years or more, having been exposed to infection as a
child when participating in mortuary feasts that were an intrinsic part of Fore
culture: that is, the cooking and consumption of the dead, every last piece of
them, in order to hasten the journey of the departed loved-ones to the land of
the ancestors.
Much later, Alpers, who had always felt discomforted
by the term cannibalism — “you don’t like to call your friends cannibals” —
would invent a new term for the Fore ritual: “transumption”. It borrowed from
the lexicon of Catholic doctrine around the Eucharistic transubstantiation of
bread into the body and blood of Christ. He defined the Fore custom as
“incorporation of the body of the dead person into the bodies of living
relatives, thus helping to free the spirit of the dead”. It was a final act of
love by the grief-stricken. Yes, as anthropologists had insisted, there was a
gastronomic element: people had given ready testimony that humans were delicious,
especially their brains. But this was a perk, not a driver, of the practice,
Alpers insisted, in papers citing the secrets shared with him and others over
decades.
In each case, it is believed the victim had
incubated the disease for an astonishing 50 years or more, having been exposed
to infection as a child when participating in mortuary feasts.
Despite the deep significance mortuary feasts held for
the Fore people and their neighbours, by 1960 the rites had almost entirely
ceased, at the insistence of Australian administrators. Immediately, the
epidemic began to ease — new cases among children vanished virtually overnight.
Today, the apparent disappearance of the disease means
there’s little more information likely to be gleaned from kuru’s
ground zero. As a consequence, this month, the funding that has flowed to
Goroka from London since 1996 — when “mad cow” disease (bovine spongiform
encephalopathy, or BSE) crossed the species barrier into humans and sent
British researchers scurrying to PNG looking for insights from the closely
related kuru epidemic — finally dries up. And routine field
surveillance will come to an end.
There may well be one or two elders who still carry
the disease, but there's no expectation that the surveyors’ last sweep
through kuru country will yield another case. Word now travels
fast if there’s so much as a suspect shiver in the most far-flung village, and
it quickly finds its way to the limestone cottage in Fremantle, Western
Australia, where Alpers retired after leaving his post in Goroka as chief of
the PNG Institute of Medical Research in 2000.
The walls of Alpers’s home are lined with books on PNG
and hung with its artifacts and art. Only a couple of years ago he trekked back
into the highlands after being summoned to a rumoured case that turned out to
be Parkinson’s disease. “Kuru is still the first thing people think
[of] if anyone gets a bit shaky,” the professor says. “It’s an extremely
powerful disease, horrible to live with, and horrible to see someone die of.
People are still very much afraid of it.”
Alpers remembers the tragedy all too well. In medical
literature, the investigation of this “extraordinary disease… will continue to
have long-standing significance for neurology, infectious disease and public
health”, as papers to the landmark Royal Society kuru meeting
in London in 2008 observed. But for Alpers it is a story populated by
individuals with names and faces, children and mothers he tended and held in
his arms in the days and weeks before they died, some of whom he cut open
within hours of their deaths, searching for the truth of the powerful agent
that had claimed them.
The survey teams may have finally left the field, but
in Fremantle Alpers continues to sift methodically through his kuru archive,
looking for new insights. He is still following the trail into the next
awakening.
COURTESY MICHAEL ALPERS
Professor Alpers arrived in Papua New Guinea in
1961, a “disaffected” medical student. What began as an adventure has become
his life’s work.
IT WAS WHEN he read the first reports of the
mysterious kuru in the Adelaide Advertiser in
1957 that Michael Alpers — a self-described “disaffected” medical student —
became intrigued. A team of local scientists were involved in the early
investigation of the disease and Alpers lobbied them to go to PNG, securing a
post for himself as a medical officer for the Australian administration which
was then considering trying to quarantine the infected region, in a desperate
bid to contain the epidemic.
Alpers flew into the wild frontier highlands town of
Goroka in 1961. Systematic medical investigation into kuru was
already well underway, initiated by local district medical officer Dr Vincent
Zigas and led by American scientist Dr Carleton Gajdusek, a brilliant, dynamic
and controversial figure who would become Alpers’s friend and collaborator, and
who later won the Nobel prize for his seminal work. A husband-and-wife team of
Australian anthropologists, Robert and Shirley Glasse (later Lindenbaum), were
also deep in the field, looking for clues in cultural practices and diet.
Alpers spent his first weeks enlisted in a crash
course in linguistics that he credits with priming him to deeper engagement
with the strange reality he was about to enter. “I learned about languages that
had never been written down, about the difference between phonetics and
phonemics. It made me realise these languages were extremely complex. Everyone
assumed in the outside world — and sometimes still do — that these were
primitive people. Well, the languages certainly weren’t primitive, and nor was
the culture based around the available technology.”
He ventured deep into the kuru heartland,
spending “a couple of months walking around, talking to people”. He recalls
receiving a particularly warm welcome in a village called Waisa, a solid hour’s
trek from the nearest road but smack in the heart of epidemic. “People said
‘Come, you’re very welcome,’ and I settled.” They built him a hut, which was
replaced in time by a house fitted with the luxuries of a water supply and a
generator. It would become his home — and later that of his own young family —
for long periods. A newer version of it still shelters researchers, and served
as the field headquarters for the UK’s Medical Research Council Prion Unit.
While kuru was Alpers’s focus, he
could not fail to see the community’s other urgent medical needs. “I trained a
couple of young men in the village to read and write, to dress sores and to
give injections and keep records, and we set up a medical clinic. People came
from valleys miles away. Everyone at that time had tropical ulcers… fortunately
they respond excellently to penicillin. Word got around.”
“It’s an extremely powerful disease, horrible to
live with, and horrible to see someone die of. People are still very much
afraid of it.”
He met Carleton Gajdusek in the field in early 1962.
“He’d upset lots of people. Everyone warned me against him, but by then we knew
that kuru was like scrapie [a transmissible, fatal brain
disease which had long occurred in sheep, and was familiar to veterinarians but
few others]. Carleton wanted to test the idea that kuru was
also transmissible, and I did too, so we joined forces. We planned an
experiment — collecting autopsy samples [from kuru victims],
putting them into chimpanzees, and then following them for 10 years.” (Alpers
stood by — and remains — fiercely defensive of Gajdusek over a murky episode in
later years where he was disgraced and jailed for a year for child molestation.
He died in 2008.)
The immediate challenge for Alpers was collecting the
autopsy tissue from afflicted brains. “When I first got there the local kiap [the
vernacular for the ranks of Australia’s all-powerful field officers — in Okapa]
said ‘absolutely not, people are fed up [with autopsies], they’ve disturbed
everyone’.” Alpers determined much of the distress was due to the bodies being
carted to hospital for examination and then not promptly returned.
His solution was to conduct limited autopsies out in
the home villages, assisted by his trained aides and the families of the dead.
This had the added benefit of securing fresh tissue very soon after death. He
told communities he wanted the brain, nothing else, and that this donation
would help scientists find an answer to the deaths. While most villagers were
convinced that sorcery was the cause, their experience of the new medical
clinics had taught them the concept of “germs” which were treatable. And they
were desperate enough to give it a try.
Over the following months Alpers gained autopsy
approval from the families of several people dying of kuru.
Everyone understood too well that no-one recovered from kuru, which
progressively stole control, mobility, speech but, tragically, not always
faculty from the afflicted. Bursting into gales of uncontrollable laughter was
another cruel quirk of the disease. “So having established the fact I had permission
to do an autopsy I then would go to the kiap and he would
provide a coroner’s certificate — in advance — authorising it,” says Alpers. As
death approached, Alpers would move into the patient’s village, and wait.
It could be a long process. Weeks, usually. “You
couldn’t do anything else but hang around, a bit like a ghoul. And it normally
took a long time even after the patient was moribund, (almost) paralysed, but
subsisting on sips of sugar water.” Alpers would ready his instruments and
prepare a hut for the autopsy, setting out labelled, sterile vials for the
tissue he would soon collect.
COURTSEY MICHAEL ALPERS
Kigea, an 11-year-old girl from Waisa village
who died of kuru. Samples from her brain led directly to the discovery that the
disease was capable of crossing the species barrier.
On the professor’s Fremantle kitchen table lies a
black and white photograph of the little girl whose story he now recounts, so
many years later. She was the second of five field autopsies Alpers conducted
during that period. The photo is a still taken from some of the kilometres of footage
he filmed over the years, to document the progress of the disease. The girl is
leaning on a stick in front of some village huts, looking shyly into the
camera. “That’s Kigea,” he says, tapping the picture. “She was from my own
village, Waisa. A wonderful little 11-year-old girl who died of kuru.”
Her end was lingering and awful. Her father despaired and ran away until it was
over; her mother had already long-since been claimed by kuru, as so
many young women were.
“The extraordinary thing was that I could still make
contact. I remember asking Kigea the day before she died to put her tongue out.
She was in this locked-in state, but she wasn’t paralysed, and she understood
me talking to her. It was a terrible situation for everybody.” Finally, Alpers received
the call — she was gone.
After each death, he says, “I would go and talk to the
family again, and say, ‘Okay?’. They had participated in cutting up bodies in
the past — so that was not an unusual activity for them. We had to clear a few
people — particularly the women who were wailing. But some of the women stayed.
The ones involved put on masks to protect the tissue and I had gloves.
“The father, or a close relative, would hold the head,
and I would take the top of the skull off with a bone handsaw. It would take
maybe 20 minutes… like cutting an avocado. I would go to particular parts of
the brain… take out small cubes. My assistant would hold out the bottle that
was relevant, take the lid off, and I’d pop it in.
“Then I’d take the whole brain out and put it in a
bucket full of formalin and cotton wool so it wouldn’t be deformed, and put the
lid on. All our samples would go into an insulated box. Then I put the skull
cap back on, and sewed up. Then we said goodbye… gave everyone a hug, and took
off. I did this five times. It was enough.”
The insulated box would be taken immediately to the
station at Okapa and put in the freezer. The next morning a chartered aircraft
would come to collect it and fly it to Lae.
From Lae the box would catch a flight direct to
Melbourne, where it was collected by a hematologist from the Commonwealth Serum
Laboratories, who would store the tissue in a deep freezer until it could be
sent to the United States National Institutes of Health in Washington DC where
Carleton Gajdusek had assembled some chimpanzees in a primate facility for the
next phase of the experiment.
“The father, or a close relative, would hold the
head, and I would take the top of the skull off with a bone handsaw. It would
take maybe 20 minutes… like cutting an avocado.”
In early 1964 Alpers followed the samples to
Washington, where he would spend the next four years exploring kuru’s
epidemiology and genetics, but even at that distance, the emotional backwash
was inescapable. By now the tissue he had taken from Kigea and another young
boy called Eiru had been inoculated into a pair of chimps — Daisey and
Georgette — and Alpers would visit them twice a week, examining them, shooting
footage, growing fond of them and their quirks and characters. “Chimps are so
close to humans it made them difficult to use in lots of ways, but we felt we
had to do it.”
Two years into the experiment, Daisey and Georgette
started behaving strangely. Their gait changed, they had difficulty walking,
and lost co-ordination. When they couldn’t pick up pieces of apple and put them
to their mouths they improvised, using their lips to scoop the apple from the
ground. Alpers had seen it all before.
“One day I was examining them and wrote down ‘clinical
impression — kuru’. It was just striking. The tremors, the gait…
the intension tremor which is a classic sign of cerebellar disease, which is
what kuru is.” Gajdusek was again in PNG and Alpers sent a
telegram summoning him back. By the time he arrived a week later, “Daisey was
falling all over the place… it was awful. But at the same time there was this
elation that our experiment was going to be successful.”
Alpers was convinced Daisey was sick from the agent
that had come to her from Kigea, and Georgette from Eiru’s brain, but it would
be several more months before that could be proved, with samples taken from
Georgette’s brain at autopsy travelling to London for scrutiny by a
neuropathologist.
The day the telegram arrived back in Washington
advising that the chimp’s brain pathology was “indistinguishable” from
human kuru “we knew transmission was true”. Alpers, Gajdusek
and their colleague Joseph Gibbs “wrote our paper in a day, dividing it in
three, and posted it at midnight”.
Unusually the paper identified Kigea and Eiru — as
well as Daisey and Georgette — each by name. Normal scientific convention is to
scrub the documentation clean of such emotionally charged contaminants as
identity. But in this instance, somewhere in their haste, the scientists’
instinct was to give credit where it was painfully due.
The paper appeared in the journal Nature,
just two weeks later. It was a watershed finding, identifying kuru as
a new category of infectious disease that caused the degeneration of the brain
and nervous system, one that was capable of crossing the species barrier and
which passed via unidentified agents lurking within brain matter. These agents
would later be identified as a single infectious, self-propagating protein —
which broke all previously assumed rules, in that they did not possess nucleic
acid. They were given the moniker “prions”, and their identification earned
another scientist (Stanley B. Prusiner) a Nobel prize. Prions bore the
distinction of being the first new pathogen identified in more than a century.
TONY ASHBY
Professor Alpers hiked into Papua New Guinea's
wild highlands, succumbing en route to a mystery, a mission and a culture.
MOMENTOUS AS THE 1966 breakthrough was, kuru remained
elusive. What was the mechanism spreading the contagion? Carleton Gajdusek
resisted what he felt was the too-glib notion that consumption of human flesh
was to blame. He argued that the infection might have travelled through cuts or
sores or dabbing of eyes during ritual handling of the dead’s organs.
Local Kiap Jack Baker reckoned the scientists were
overthinking it, overlooking the obvious.
Alpers had by then spent several years reviewing the
epidemiology of the disease, trawling through data collected by patrol
officers, scientists and missionaries. Their work had been ably assisted by the
Fore people’s formidable collective memory — “cause of death is always known,
even going back three generations”, explains Alpers.
He combined the charts with the insights of
anthropologists working in the field, and the secrets of Fore ritual that had
been entrusted to him. The Fore’s complex eschatology declared that each
individual had five souls; that after death they travelled the land on a kind
of farewell tour from which ultimately — assuming various rituals over a period
of years were honoured — they would be reunited in the land of the ancestors.
The most efficient path to this hereafter was for the body to be eaten.
As Alpers, with Jerome Whitfield and other colleagues
summarised in a recent paper: “If the body was buried it was eaten by worms; if
it was placed on a platform it was eaten by maggots; the Fore believed it was
much better that the body was eaten by people who loved the deceased than by worms
and insects. By eating their dead, they were able to show their love and
express their grief.”
It was the women’s responsibility to eat the dead,
grinding the bones and cooking the flesh, indulging their children along the
way with the tastiest bits. Particular body parts were given to particular
female kin. Although small boys joined in the feasting, they were generally
excluded after about age 10.
By 1964 Alpers had solid figures on kuru deaths
spread over seven years. “I compared the data for 1957, ’58 and ’59 with ’61,
’62 and ’63, and looked for any changing patterns. Overall, there was not much,
but if you looked at the young kids, the disease had essentially disappeared —
even in that short time. This was a major change.” Obviously there had been some
social or environmental shift. But so much in the Fore world had been in a
state of upheaval during that era.
“We made a list, Carleton and I, and there were lots
of changes. The introduction of new foods, new animals, the cessation of
certain activities. But the one that was biologically the most relevant was the
mortuary practices, at least in my view.” A couple of years later, field
surveys confirmed the disease had died out in children younger than 10 — which
fitted with the kiaps effectively administering new rules of
behaviour through the district. The rules were, says Alpers, “No fighting,
build roads, no cannibalism, no child marriage, and plant coffee. And they did it.”
“The Fore believed it was much better that the
body was eaten by people who loved the deceased than by worms and insects. By
eating their dead, they were able to show their love and express their grief.”
When Alpers put his data together for a presentation
in Washington in 1967 “the argument for cannibalism — and I don’t use that term
anymore, but it was used then — was compelling. Everything fitted. Why did
women and children get the disease? Because they were the ones that carried out
the practice — the men didn’t. It explained why it was dying out in young
children — because the kiaps had proscribed cannibalism. You
could also conclude that the disease was not being transmitted vertically from
mother to child. No one born since 1960 was coming down with kuru.
The penny dropped”.
The humbling lesson for scientists and doctors was
that while their labours might have helped solve the puzzle, they had not
halted the disease. The honour for the life-saving intervention belonged to the
officers, both black and white, who administered the new laws of the land.
One aspect of the mystery remained unsolved: where had
the disease started? Robert and Shirley Glasse had walked the trail through the
signposts of Fore memory to a location and a moment early last century, tracing
oral accounts of the disease appearing from the 1910s. In 1970 Alpers wrote a
paper proposing that kuru had spread from a single case of
spontaneous Creutzfeldt-Jakob Disease (CJD) — a rare but real and well
documented occurrence in any human population. Ordinarily, such an event might
present an individual and a family with an unfathomable tragedy, but it ended
there. However, in a culture in which brain tissue was consumed through the
Fore’s funeral rituals, that single episode amplified over a generation or two,
and then took off.
Genetic analysis would later provide evidence
supporting this theory. It would also yield a few more surprises: some of these
would be critical in managing future disease; others would go back through
history, identifying skeletons in the darker recesses of humanity’s closet.
When Michael Alpers arrived in New Guinea, in 1961,
and visited villages where the women of child-bearing age were all but gone,
the view was that the Fore were on the brink of extinction. But what if, in a
classic enunciation of Darwinian natural selection, the Fore were merely en
route to a population bottleneck, from which the survivors would emerge with
more protective genetic pedigrees?
In 2003, Alpers was one of the authors of a
sensational paper published in the journal,Science. A new round of
genetic analysis of elderly survivors of Fore mortuary feasts had revealed they
possessed a particular form of a gene which seemed to give them genetic
resistance to kuru. Wider sampling across 2000 people from other
cultures found the same chromosomal quirk. The authors argued that the
widespread appearance of this prion-protective gene indicated natural selection
had been at work before in this context, and that the consumption of human
flesh — and consequent outbreaks of infectious disease — had occurred widely in
the remote human past.
TONY ASHBY
In his Fremantle home, Professor Michael Alpers
reflects on his 50-year mission to eradicate kuru. Patrols will end this year.
WITH KURU HAVING ALL BUT VANISHED,
and the mechanism for its spread having been eradicated, the whole episode
might have quickly disappeared (except in the memories of the depleted Fore)
into the annals of curiosity. But then came the “mad cow” crisis. It made international
headlines when BSE manifested in British beef in the mid-1980s, as a
consequence of beasts having been reared on meal derived from the recycled
offal of their own kind. The fear was that consumption of diseased beef would
see the disease spread to humans.
That fear was realised when the infection turned up in
human form as variant Creutzfeldt-Jakob Disease (vCJD), from 1996. With 176
cases confirmed to date in the UK alone (another 49 are recorded elsewhere,
half of them in France), it has not reached the epidemic proportions once
anticipated. Part of its management and containment is credited to the early
recognition of its similarities to kuru. Comparing the medical film
archives, the British casualties of vCJD look like pale ghosts of the Fore, their
faces contorting into the same anguished shapes, their limbs staggering and
trembling in a now familiar dance.
“I spoke to Michael before vCJD appeared, on the basis
that we thought it might transmit to humans,” recalls neurologist Professor
John Collinge, director of the UK Medical Research Council Prion Unit. “Of
course it turned out that it did. It seemed to me that kuru was
the major experience we had of one of these diseases. And we had better get to
know as much about it as we can.”
Soon Collinge was en route to PNG. His first urgent
question of the team on the ground was whether prion disease really could
incubate for upwards of 50 years? The findings by his own unit, published
in The Lancet, would confirm it. “This was quite extraordinary. It
was clear these were long transmissions. And understanding that was then very
important in the UK and other countries with vCJD.
“We [also] wanted to see what strain or strains of
prions caused kuru. We actually found two different strains
in kuru, which were two of the same strains that cause sporadic CJD
which occurs rarely, and at random, in all human populations.
For Collinge, like Alpers, the journey to PNG’s kuru country
took him into uncharted territory. At home he had a still undefined
public-health emergency to manage, together with the demands of voracious
first-world. How many people had been exposed to killer hamburgers? How many
might ultimately be struck down?
In PNG Collinge found himself negotiating more nuanced
but no-less confronting questions. What were the obligations of medical
investigators, pursuing a quest on behalf of their own populations, to people
of the developing world? “We couldn’t turn up as westerners and say ‘we’re only
interested in kuru — you’re dying of malaria, but that is not
our interest’. It was ethically essential that we work with the community,
contribute… tend to patients with common infectious diseases that might be
lethal without treatment, in the same way they were helping us with our medical
problem.”
What were the obligations of medical
investigators, pursuing a quest on behalf of their own populations, to people
of the developing world?
The outcome of this thinking is that an enduring
funding and co-operation agreement was forged between London and Goroka. Over the
years, the UK project helped build three schools in the kuruarea,
trained teachers and established clean water supplies.
At the heart of the project were the critical clinical
lessons to be learned from the Fore. Collinge cited these to the British press,
priming his home audience for the likelihood of a second wave of vCJD cases.
This warning emerged from genetic analysis of the long-term survivors of kuru,
who have inherited a profile that acts to delay onset. Scrutiny of kuru cases
reveals that a key gene shapes the body’s defences against the disease, and it
exists in two forms: version-m and version-v. People with two identical copies
MM or VV (one copy of the gene from each parent) were the first to get kuru,
while those with one M and one V form (MV) might survive for decades. The same
genetic profile is underwriting vCJD, the proportions suggesting another 250
delayed cases may emerge in the UK in the next few decades.
But there is another level of concern in the UK, says
Collinge, around what is sometimes described as “modern” cannibalism — the
recycling of blood, tissue and organs through medicine. In July this year,
while Britain was distracted by the Olympics festival, the UK Health Protection
Agency published findings from a survey of appendix tissue removed routinely
from Britons in an attempt to measure the prevalence of vCJD across the
population. It identified abnormal prions in 16 of
32, 441 cases.
“I think that is quite a worrying figure,” Collinge
says, “suggesting that one in 2000 people in the UK population are infected.
Now these individuals are healthy. Will they ever develop CJD? Are they
individuals with very long incubation periods like we see inkuru? Some
of them possibly. But I suspect a majority of them will be genuine carriers —
infected, but they will never develop the disease themselves. They do, though,
represent a risk to others if they are blood donors or donate organs. This is
an ongoing public health issue in the UK… and kuru still has
things to say about that.”
In the broader medical context, kuru continues
to provide insight into neurodegenerative diseases such as Alzheimer’s and
Parkinson’s. “It turns out that all these diseases involve accumulation of
proteins… They all involve one of the body’s own proteins going wrong and
forming clumps of material in the brain. It’s this process that seems to be
critical to what is going on in prion disease [such as kuru and
vCJD], and it’s now becoming increasingly apparent that similar sorts of
processes are at work in Alzheimer’s and Parkinson’s,” Collinge says.
IT'S THREE YEARS SINCE the kuru pathogen
stirred to claim its most recent victim, a 61-year-old woman from a far-flung
hamlet right in the heart of the defined disease sector. It had slept within
her for over 50 years — suppressed, according to the latest findings — by an
accident of chromosomes programmed to resist the infection. She can have been
only a young girl when she ate the morsel that would eventually kill her — very
likely taking it from the hand of her mother or one of her aunts.
There is another level of concern in the UK,
says Collinge, around what is sometimes described as “modern” cannibalism — the
recycling of blood, tissue and organs through medicine.
In the medical literature today kuru is
recognised not as “an exotic, strange and unique disease caused by cannibalism
on a remote island”, but as representative of a whole novel class of disease
and carrying powerful, enduring lessons for human health.
In PNG’s Eastern Highlands, the disease is an unforgotten
horror, one many still blame on sorcery, even if they give credence to the
interventions and arguments of outsiders who tell them that it was their
funeral practice that spread the curse. Through the stories of the kuru scouts
and the presence of so many outside researchers and doctors over so many years,
there is also wide understanding that the Fore’s tragedy has provided hard
lessons to the wider world.
“In some ways the story has come to its end,” Alpers
says, even as he knuckles down to a review of every one of 2,700 kuru files,
a task he estimates will take him two years. There are one or two angles in
them he hasn’t explored. Meanwhile in laboratories elsewhere, scientists
continue to poke and probe secretive prions. “It seems now that every neurodegenerative
disease — Alzheimer’s, Parkinson’s, Huntington’s — all have a similar prionic
process, though they are not infectious in the same way.”
There was supposed to be some fanfare this October, to
mark the end of 50-plus years of field surveillance of kuru. Alpers
and Collinge and others were to return to Goroka. But the plans unravelled
after a death in the family of one of the principal players. Instead, a low-key
celebration will take place at some point. Meanwhile the project overseers
invited the ranks of their retired and serving kuru field
reporters to nominate what they might like to mark the moment. A medal? A
citation?
“They wanted boots,” Alpers says, so that is what they
got – good, solid walking boots. After all those miles, up and down all those
mountains, on the trail of an elusive killer, the kuru trackers
proudly lace up their hard-earned trophies and continue on their way.
For more information:
‘The end of kuru: 50 years of research into an extraordinary disease’, 2008
Special Edition, Philosophical Transactions of the Royal Society, edited by John Collinge and Michael Alpers.
SOURCE:
http://www.theglobalmail.org/feature/the-last-laughing-death/470/
