Kuru (disease)
Encyclopedia
Kuru is an incurable degenerative neurological disorder
that is a type of transmissible spongiform encephalopathy
, caused by a prion
found in humans. The term "kuru" derives from the Fore word "kuria/guria" ("to shake"), a reference to the body tremors that are a classic symptom of the disease; it is also known among the Fore as the laughing sickness due to the pathologic bursts of laughter people would display when afflicted with the disease. It is now widely accepted that Kuru was transmitted among members of the Fore tribe of Papua New Guinea
via cannibalism
.
Awande Hospital was built in 1961 in the Eastern Highlands to accommodate kuru patients and research. Kuru was first noted in 1952-1953 by anthropologists R. M. and C. H. Berndt among the Fore, Yate, and Usanufa people. Charles O. Pfarr, Lutheran Medical Services was brought to the area by tribal persons and reported the disease to Australian authorities. Dr. Vincent Zigas, District Medical Officer began observation. Blood specimens and brain tissue were sent to Melbourne. In 1957, Dr. D. C. Gajdusek of the National Institute of Health joined Dr. Zigas at the research center. Sister Eva Hasselbusch of Germany joined the hospital in 1959 to take care of the patients. Sister Maria Horn of Germany was the first trained sister to work with the doctors to study the disease. By 1968 the hospital ceased to function as a Kuru hospital and was closed. (1886-1986, The Lutheran Church in Papua New Guinea by Herwig Wagner and Hermann Reiner)
The disease was researched by Daniel Carleton Gajdusek
as part of an international collaboration with Australian doctor (now Professor) Michael Alpers. In the mid-1960s Alpers collected post-mortem brain tissue samples from an 11-year-old Fore girl, Kigea, who had died of kuru. He took these samples to Gajdusek in the USA, who then injected two chimpanzees with the infected material. Within two years, one of the chimps, Daisy, had developed kuru, demonstrating that the unknown disease factor was transmitted through infected biomaterial and that it was capable of crossing the species barrier to other primates.
In 1976 Gajdusek, along with Baruch S. Blumberg, was awarded the Nobel Prize in Physiology or Medicine
for showing that kuru was transmissible to chimpanzees. This was the first time that this group of encephalopathies had been demonstrated to be infectious and therefore a major step forwards in their investigation. As kuru is the only epidemic
of human prion
disease in known human history, it has provided important insights into the variant CJD.
s and is related to Creutzfeldt-Jakob disease
(CJD). It is best known for the epidemic
that occurred in Papua New Guinea
in the middle of the twentieth century, and earlier. Although it is considered a transmissible prion disease, there is some evidence that the origin of the outbreak was due to consumption of an individual (cannibalism
) with sporadic CJD, thus implying a common pathophysiology.
ataxia, preceded by headaches, joint pains and shaking of the limbs. Trembling is present in almost all patients with transmissible spongiform encephalopathy
, Kuru is also known as "shiver."
The preclinical or asymptomatic
phase, also called the incubation period
, lasts between possibly 5 to 20 years following initial exposure. The clinical stage lasts an average of 12 months.
The symptoms of Kuru are then broken down into three specific stages. The first, ambulant stage, exhibits unsteady stance and gait, decreased muscle control, tremors, deterioration of speech and dysarthria (slurred speech). In the second stage, sedentary stage, the patient is incapable of walking without support, suffers ataxia (loss of muscle coordination) and severe tremors. Furthermore, the victim is emotionally unstable, depressed, yet having uncontrolled sporadic laughter. Interestingly, the tendon reflexes are still normal at this point. Finally, the patient enters terminal stage, at which point he is incapable of sitting without support, suffers severe ataxia (no muscle coordination), is unable to speak, is incontinent (unable to restrain natural discharges/evacuations of urine or feces), has dysphagia (difficulty swallowing), is unresponsive to his surroundings, and acquires ulcerations (sores with pus and necrosis). An infected person usually dies within 3 months to 2 years after the first symptoms, often because of pneumonia or pressure sores infection.
(CJD). Alpers and Lindenbaum's research conclusively demonstrated that kuru spread easily and rapidly in the Fore people due to their endocannibalistic
funeral practices, in which relatives consumed the bodies of the deceased to return the "life force" of the deceased to the hamlet, a Fore societal subunit. The dysmorphism evident in the infection rates — kuru was 8–9 times more prevalent in women and children than in men at its peak — is because while the men of the village took the choice cuts, the women and children would eat the rest of the body including the brain, where the prion particles were particularly concentrated. There is also the strong possibility that it was passed on to women and children more easily because they took on the task of cleaning relatives after death and may have had open sores and cuts on their hands. Although ingestion itself of the prion particles can lead to the disease, there was a high degree of transmission if the prion particles could reach the subcutaneous tissue. With elimination of cannibalism because of Australian colonial law enforcement and the local Christian missionaries' efforts, Alpers' research showed that Kuru was already declining among the Fore by the mid-1960s, although cases continued to appear for several decades more, and the last sufferer died in 2005. However, the mean incubation period of the disease is 14 years and cases were reported with latencies of 40 years or more for those who were most genetically resilient.
, and others, showed in their genetic and clinical assessment that people who survived the epidemic in Papua New Guinea were carriers of a prion-resistant factor. Mead's group has shown the source of immunity to be the inheritance of a genetic variant of prion protein G127V. This work remains breaking news as of November 22, 2009, and further implications of the discovery including evidence for rapid natural selection
of populations are being discussed.
Neurological disorder
A neurological disorder is a disorder of the body's nervous system. Structural, biochemical or electrical abnormalities in the brain, spinal cord, or in the nerves leading to or from them, can result in symptoms such as paralysis, muscle weakness, poor coordination, loss of sensation, seizures,...
that is a type of transmissible spongiform encephalopathy
Transmissible spongiform encephalopathy
Transmissible spongiform encephalopathies , also known as prion diseases, are a group of progressive conditions that affect the brain and nervous system of many animals, including humans. According to the most widespread hypothesis they are transmitted by prions, though some other data suggest an...
, caused by a prion
Prion
A prion is an infectious agent composed of protein in a misfolded form. This is in contrast to all other known infectious agents which must contain nucleic acids . The word prion, coined in 1982 by Stanley B. Prusiner, is a portmanteau derived from the words protein and infection...
found in humans. The term "kuru" derives from the Fore word "kuria/guria" ("to shake"), a reference to the body tremors that are a classic symptom of the disease; it is also known among the Fore as the laughing sickness due to the pathologic bursts of laughter people would display when afflicted with the disease. It is now widely accepted that Kuru was transmitted among members of the Fore tribe of Papua New Guinea
Papua New Guinea
Papua New Guinea , officially the Independent State of Papua New Guinea, is a country in Oceania, occupying the eastern half of the island of New Guinea and numerous offshore islands...
via cannibalism
Cannibalism
Cannibalism is the act or practice of humans eating the flesh of other human beings. It is also called anthropophagy...
.
History
Kuru was first noted in the Fore tribe of the Eastern Highlands Province of Papua New Guinea as Australian administrators explored the area in 1953–1959. Kuru (Keru) was reported by W. T. Brown in Kainantu Patrol Report No 8 of 1953/54 (13 January 1954 - 20 February 1954.) .. "The first sign of impending death is a general debility which is followed by general weakness and inability to stand. The victim retires to her house. She is able to take a little nourishment but suffers from violent shivering. The next stage is that the victim lies down in the house and cannot take nourishment and death eventually ensues." The same reports described the cannibalism practised by the Fore people. It was in the late 1950s that the full extent of the disease was realized, after it had reached large infection rates in the South Fore of the Okapa Subdistrict, though the agent was unknown.Awande Hospital was built in 1961 in the Eastern Highlands to accommodate kuru patients and research. Kuru was first noted in 1952-1953 by anthropologists R. M. and C. H. Berndt among the Fore, Yate, and Usanufa people. Charles O. Pfarr, Lutheran Medical Services was brought to the area by tribal persons and reported the disease to Australian authorities. Dr. Vincent Zigas, District Medical Officer began observation. Blood specimens and brain tissue were sent to Melbourne. In 1957, Dr. D. C. Gajdusek of the National Institute of Health joined Dr. Zigas at the research center. Sister Eva Hasselbusch of Germany joined the hospital in 1959 to take care of the patients. Sister Maria Horn of Germany was the first trained sister to work with the doctors to study the disease. By 1968 the hospital ceased to function as a Kuru hospital and was closed. (1886-1986, The Lutheran Church in Papua New Guinea by Herwig Wagner and Hermann Reiner)
The disease was researched by Daniel Carleton Gajdusek
Daniel Carleton Gajdusek
Daniel Carleton Gajdusek was an American physician and medical researcher who was the co-recipient of the Nobel Prize in Physiology or Medicine in 1976 for work on kuru, the first human prion disease demonstrated to be infectious....
as part of an international collaboration with Australian doctor (now Professor) Michael Alpers. In the mid-1960s Alpers collected post-mortem brain tissue samples from an 11-year-old Fore girl, Kigea, who had died of kuru. He took these samples to Gajdusek in the USA, who then injected two chimpanzees with the infected material. Within two years, one of the chimps, Daisy, had developed kuru, demonstrating that the unknown disease factor was transmitted through infected biomaterial and that it was capable of crossing the species barrier to other primates.
In 1976 Gajdusek, along with Baruch S. Blumberg, was awarded the Nobel Prize in Physiology or Medicine
Nobel Prize in Physiology or Medicine
The Nobel Prize in Physiology or Medicine administered by the Nobel Foundation, is awarded once a year for outstanding discoveries in the field of life science and medicine. It is one of five Nobel Prizes established in 1895 by Swedish chemist Alfred Nobel, the inventor of dynamite, in his will...
for showing that kuru was transmissible to chimpanzees. This was the first time that this group of encephalopathies had been demonstrated to be infectious and therefore a major step forwards in their investigation. As kuru is the only epidemic
Epidemic
In epidemiology, an epidemic , occurs when new cases of a certain disease, in a given human population, and during a given period, substantially exceed what is expected based on recent experience...
of human prion
Prion
A prion is an infectious agent composed of protein in a misfolded form. This is in contrast to all other known infectious agents which must contain nucleic acids . The word prion, coined in 1982 by Stanley B. Prusiner, is a portmanteau derived from the words protein and infection...
disease in known human history, it has provided important insights into the variant CJD.
Causes
Kuru is believed to be caused by prionPrion
A prion is an infectious agent composed of protein in a misfolded form. This is in contrast to all other known infectious agents which must contain nucleic acids . The word prion, coined in 1982 by Stanley B. Prusiner, is a portmanteau derived from the words protein and infection...
s and is related to Creutzfeldt-Jakob disease
Creutzfeldt-Jakob disease
Creutzfeldt–Jakob disease or CJD is a degenerative neurological disorder that is incurable and invariably fatal. CJD is at times called a human form of mad cow disease, given that bovine spongiform encephalopathy is believed to be the cause of variant Creutzfeldt–Jakob disease in humans.CJD...
(CJD). It is best known for the epidemic
Epidemic
In epidemiology, an epidemic , occurs when new cases of a certain disease, in a given human population, and during a given period, substantially exceed what is expected based on recent experience...
that occurred in Papua New Guinea
Papua New Guinea
Papua New Guinea , officially the Independent State of Papua New Guinea, is a country in Oceania, occupying the eastern half of the island of New Guinea and numerous offshore islands...
in the middle of the twentieth century, and earlier. Although it is considered a transmissible prion disease, there is some evidence that the origin of the outbreak was due to consumption of an individual (cannibalism
Cannibalism
Cannibalism is the act or practice of humans eating the flesh of other human beings. It is also called anthropophagy...
) with sporadic CJD, thus implying a common pathophysiology.
Presentation
Kuru causes physiological as well as neurological effects that ultimately lead to death. It was endemic among the Fore tribe of Papua New Guinea and was confined to the Fore population and those nearby populations with whom they intermarried. It is characterized by truncalTorso
Trunk or torso is an anatomical term for the central part of the many animal bodies from which extend the neck and limbs. The trunk includes the thorax and abdomen.-Major organs:...
ataxia, preceded by headaches, joint pains and shaking of the limbs. Trembling is present in almost all patients with transmissible spongiform encephalopathy
Transmissible spongiform encephalopathy
Transmissible spongiform encephalopathies , also known as prion diseases, are a group of progressive conditions that affect the brain and nervous system of many animals, including humans. According to the most widespread hypothesis they are transmitted by prions, though some other data suggest an...
, Kuru is also known as "shiver."
The preclinical or asymptomatic
Asymptomatic
In medicine, a disease is considered asymptomatic if a patient is a carrier for a disease or infection but experiences no symptoms. A condition might be asymptomatic if it fails to show the noticeable symptoms with which it is usually associated. Asymptomatic infections are also called subclinical...
phase, also called the incubation period
Incubation period
Incubation period is the time elapsed between exposure to a pathogenic organism, a chemical or radiation, and when symptoms and signs are first apparent...
, lasts between possibly 5 to 20 years following initial exposure. The clinical stage lasts an average of 12 months.
The symptoms of Kuru are then broken down into three specific stages. The first, ambulant stage, exhibits unsteady stance and gait, decreased muscle control, tremors, deterioration of speech and dysarthria (slurred speech). In the second stage, sedentary stage, the patient is incapable of walking without support, suffers ataxia (loss of muscle coordination) and severe tremors. Furthermore, the victim is emotionally unstable, depressed, yet having uncontrolled sporadic laughter. Interestingly, the tendon reflexes are still normal at this point. Finally, the patient enters terminal stage, at which point he is incapable of sitting without support, suffers severe ataxia (no muscle coordination), is unable to speak, is incontinent (unable to restrain natural discharges/evacuations of urine or feces), has dysphagia (difficulty swallowing), is unresponsive to his surroundings, and acquires ulcerations (sores with pus and necrosis). An infected person usually dies within 3 months to 2 years after the first symptoms, often because of pneumonia or pressure sores infection.
Transmission
Beginning in 1961, Australian doctor (now Professor) Michael Alpers conducted extensive field studies among the Fore, which were supported by the work of anthropologist Shirley Lindenbaum. Their historical research with the Fore suggests that the epidemic may have originated around 1900 from a single individual who lived on the edge of Fore territory, who is thought to have spontaneously developed some form of Creutzfeldt-Jakob DiseaseCreutzfeldt-Jakob disease
Creutzfeldt–Jakob disease or CJD is a degenerative neurological disorder that is incurable and invariably fatal. CJD is at times called a human form of mad cow disease, given that bovine spongiform encephalopathy is believed to be the cause of variant Creutzfeldt–Jakob disease in humans.CJD...
(CJD). Alpers and Lindenbaum's research conclusively demonstrated that kuru spread easily and rapidly in the Fore people due to their endocannibalistic
Endocannibalism
Endocannibalism is the term which describes the practice of eating dead members of one's own culture, tribe or social group...
funeral practices, in which relatives consumed the bodies of the deceased to return the "life force" of the deceased to the hamlet, a Fore societal subunit. The dysmorphism evident in the infection rates — kuru was 8–9 times more prevalent in women and children than in men at its peak — is because while the men of the village took the choice cuts, the women and children would eat the rest of the body including the brain, where the prion particles were particularly concentrated. There is also the strong possibility that it was passed on to women and children more easily because they took on the task of cleaning relatives after death and may have had open sores and cuts on their hands. Although ingestion itself of the prion particles can lead to the disease, there was a high degree of transmission if the prion particles could reach the subcutaneous tissue. With elimination of cannibalism because of Australian colonial law enforcement and the local Christian missionaries' efforts, Alpers' research showed that Kuru was already declining among the Fore by the mid-1960s, although cases continued to appear for several decades more, and the last sufferer died in 2005. However, the mean incubation period of the disease is 14 years and cases were reported with latencies of 40 years or more for those who were most genetically resilient.
Immunity
Simon Mead of University College LondonUniversity College London
University College London is a public research university located in London, United Kingdom and the oldest and largest constituent college of the federal University of London...
, and others, showed in their genetic and clinical assessment that people who survived the epidemic in Papua New Guinea were carriers of a prion-resistant factor. Mead's group has shown the source of immunity to be the inheritance of a genetic variant of prion protein G127V. This work remains breaking news as of November 22, 2009, and further implications of the discovery including evidence for rapid natural selection
Natural selection
Natural selection is the nonrandom process by which biologic traits become either more or less common in a population as a function of differential reproduction of their bearers. It is a key mechanism of evolution....
of populations are being discussed.
Kuru in popular culture
- The 2010 documentary Kuru: The Science and the Sorcery recounts the work of Alpers, Gajdusek and their colleagues in uncovering the link between kuru and endocannibalism in the Fore and the discovery of prions as the cause of the disease.
- The Fore and kuru are a central element of the novel Dream ParkDream ParkDream Park was originally a novel set in a sort of futuristic amusement park of the same name.The books describe a futuristic form of live action role-playing games , although the term was not in use when the original novel was published. The novels inspired many LARP groups, notably the...
by Larry NivenLarry NivenLaurence van Cott Niven / ˈlæri ˈnɪvən/ is an American science fiction author. His best-known work is Ringworld , which received Hugo, Locus, Ditmar, and Nebula awards. His work is primarily hard science fiction, using big science concepts and theoretical physics...
and Steven BarnesSteven BarnesSteven Barnes is an African American science fiction writer, lecturer, creative consultant, and human performance technician....
, which includes the explanation that kuru is transmitted via endocannibalism. - In the episode "My Balancing Act" of ScrubsScrubs (TV series)Scrubs is an American medical comedy-drama television series created in 2001 by Bill Lawrence and produced by ABC Studios. The show follows the lives of several employees of the fictional Sacred Heart, a teaching hospital. It features fast-paced screenplay, slapstick, and surreal vignettes...
, J.D.John DorianJohn Michael "J.D." Dorian, M.D. is a fictional character on the American comedy-drama Scrubs, played by Zach Braff. He is the narrator and main character of the series. He provides voice-over to the series which fills the roles of his internal thoughts and an overall narration in the show, often...
misdiagnoses a patient with Kuru, causing Dr. CoxDr. CoxPercival "Perry" Ulysses Cox, M.D. , is a fictional character played by John C. McGinley on the American television comedy-drama Scrubs....
to teach him about the zebra principle. - In the 2010 post-apocalyptic action film The Book of EliThe Book of EliThe Book of Eli is a 2010 American post-apocalyptic action film directed by the Hughes brothers, written by Gary Whitta, and starring Denzel Washington, Gary Oldman, Mila Kunis, Ray Stevenson and Jennifer Beals....
people are asked to show their hands before conducting business, this is because kuru causes limb-shaking (called "the shakes" in the movie) and has become a method to recognize cannibalsCannibalismCannibalism is the act or practice of humans eating the flesh of other human beings. It is also called anthropophagy...
, as the main cause of kuru was cannibalism. - In the 2010 post-apocalyptic role-playing video game Fallout: New VegasFallout: New VegasFallout: New Vegas is a first person action role-playing video game in the Fallout series developed by Obsidian Entertainment, and published by Bethesda Softworks. The game is based in a post-apocalyptic environment in and around Las Vegas, Nevada...
, the player meets a character named "Old Ben" who recalls a story of a butcher who sold "strange meat." In the story, after the local townsfolk began consuming this meat, people began developing "the shakes" and "going mad," which Old Ben describes as only occurring from the consumption of human flesh. This is likely a reference to cannibalism being a primary cause for kuru, although the disease itself is not explicitly mentioned in the game dialog. Although at the end of Old Ben's story, he mentions that when the butcher died, people who investigated his house discovered many dismembered bodies concealed in the crawlspaces of the house. - In the episode "Theef" of The X-FilesThe X-FilesThe X-Files is an American science fiction television series and a part of The X-Files franchise, created by screenwriter Chris Carter. The program originally aired from to . The show was a hit for the Fox network, and its characters and slogans became popular culture touchstones in the 1990s...
, ScullyDana ScullyFBI Special Agent Dana Katherine Scully, M.D. is a fictional character and protagonist on the Fox television series The X-Files , played by Gillian Anderson. She also appeared in two theatrical films based on the series...
diagnoses a patient with Kuru, caused by some kind of Voodoo priest in a doctor who killed himself after a psychotic crisis. - In the novel "Meat" by Joseph D'Lacey, a town subsists on farmed humans, subsequently causing 'the shakes' to key characters in the story.
- In the 2011 video game "Dead IslandDead IslandDead Island is a first person horror action-adventure video game developed by Techland and published by Deep Silver for Microsoft Windows, Xbox 360, and PlayStation 3. It is centered on the challenge of survival on a zombie-infested open world island with a major emphasis on melee combat. It was...
", the cause of the zombie epidemic is hinted to be a mutated strain of Kuru. - In Deadtime Stories: Volume 2 by George A. Romero the first story titled "The Gorge" Hints at signs of Kuru (mostly the shakes).
- In an episode of The Love BoatThe Love BoatThe Love Boat is an American television series set on a cruise ship, which aired on the ABC Television Network from September 24,1977, until May 24,1986.The show starred Gavin MacLeod as the ship's captain...
, a man falsely claims to have contracted Kuru. Dr. Bricker dismisses the claim, saying, "not unless you've been eating your relatives!" - In the 2010 movie "I Saw the DevilI Saw the DevilI Saw the Devil is a 2010 South Korean thriller film directed by Kim Ji-woon, written by Park Hoon-jung and starring Lee Byung-hun and Choi Min-sik. The film premiered at the 2011 Sundance Film Festival and had a limited U.S theatrical release. The film was Choi Min-sik's first major role since...
" its is implied that the cannibal character has Kuru as he is displaying symptoms of uncontrollable laughter.