Kuru—Science Meets Sorcery in the Fore by ROBIN COOKE PNGK June 2021
Medical services in Papua New Guinea were poorly developed until after WWII when the Australian Government established a combined administration of the pre-war Territory of Papua and the Mandated Territory of New Guinea into the Territory of Papua and New Guinea (TPNG). Dr John Gunther, Director of Public Health, set about building hospitals and other infrastructure, and appointing staff.
The doctors he appointed were not familiar with many of the diseases they encountered, and quite a few of the diseases were unique to Papua New Guinea. The most famous of these was kuru, first officially reported among the Fore people by Patrol Officer JR McArthur in 1953.
A Lutheran mission had been established in this area in 1949 and an administration patrol post followed soon afterwards. Missionaries, government officers and visiting anthropologists all noted the occurrence of a ‘shaking’ disease, called kuru by the people. Mostly, this affected women and children of both sexes and was causing social unrest amongst the population. The disease was fatal for its victims, and it generated fear in their relatives because the people believed that kuru was the result of sorcery. People became afflicted, they said, because a sorcerer had put a spell upon them. It was the responsibility of the patients’ relatives to identify the sorcerer and kill him. This could initiate a series of payback killings. Any unexplained death, including those from pneumonia, for example, could be attributed to sorcery and generate payback.
Dr Vincent Zigas, the medical officer at Kainantu, was sent to Okapa by the new Director of Public Health, Dr Roy Scragg, to examine the problem in 1956. John Colman was the kiap who had set up the patrol post there and he enabled Zigas to examine a few patients. Zigas thought they were hysterical, but agreed that he was looking at a disease new to western medicine. Following instructions, he collected and sent samples from these patients to the Walter and Eliza Hall Institute in Melbourne (WEHI). Sir Frank Macfarlane Burnet was director of WEHI, a renowned virologist and recognised as a suitable specialist to advise medical authorities in TPNG.
In 1957 a young medical researcher from the US, Dr Daniel Carleton Gajdusek, who had earlier visited New Britain and had been working at WEHI, stopped off in Port Moresby on a return visit to New Britain. He called on Scragg who told him about kuru and the likelihood of its being a new disease. Gajdusek planned to fly to Rabaul via a stopover in Goroka. While in Goroka he contacted Zigas, saying that his flight to Rabaul included a stop at Kainantu and asking if he could possibly examine a few kuru patients during that stop. Zigas agreed. Gajdusek saw two patients and was convinced he was seeing a new disease of the nervous system. He took his bags from the plane and stayed to talk with Zigas about kuru. The next day they both went to Okapa where they were welcomed and assisted by Jack Baker, now the local kiap. On this, his first visit to Okapa, Gajdusek stayed for nine months and, with Zigas, began a detailed investigation of kuru. Using local resources, they built a hospital and began examining kuru patients.
During this time Gajdusek took up a ‘visiting’ position in the US National Institutes of Health (NIH), but located in TPNG, with the endorsement of Joe Smadel, an Associate Director of NIH. This provided the advantage of some logistical support and access to the laboratories of NIH. This support from NIH was important because, during this period, Gajdusek, at the instigation of Burnet, had become persona non grata with the Department of Public Health and Zigas was ordered to leave Okapa and return to his post at Kainantu. Gajdusek was seen as an unauthorised interloper on an Australian problem. Gajdusek stayed in the area, continued to care for his patients, patrolled extensively with Jack Baker, and eventually won the grudging respect of the administration.
While working together Zigas and Gajdusek defined the clinical signs of kuru. These included the fact that it particularly affected children and young women and that it began with lack of movement control and clumsiness in gait. The tremor associated with kuru (‘kuru’ is the Fore word for shivering) originated in the cerebellum, part of the brain concerned with maintaining balance.
Gradually the lack of movement control became more disabling and sufferers showed irregular and involuntary movements. The ‘laughing’ associated with a phase of kuru was real and due to emotional lability and hence its description in the press as ‘laughing’ disease. Eventually, patients could no longer sit up, became incontinent, developed sores and all eventually died of either starvation, pneumonia or progression of the disease to the vital centres of the brain.
Zigas and Gajdusek devised a useful test to detect early cases. They simply asked possible cases to stand on one leg. This had some similarity to the test used by local men to determine whether a potential bride had kuru. They observed them crossing one of the fast-flowing streams in the district by means of the traditional bridge, i.e. a thin tree trunk laid from one bank to the other. If they were unable to cross safely, they were suffering from poor balance which indicated that they had kuru.
Having defined the clinical nature of kuru they set about examining its importance in the population. They mapped the place of occurrence of all their cases and found that most were confined to the Fore language group, with a higher frequency in the south than in the north. Other cases were also seen in nine contiguous language groups. In 1958 this population of 40,000 people suffered about 200 deaths from kuru annually.
By the time of their first scientific papers on the subject in late 1957—in the New England Journal of Medicine and the Medical Journal of Australia—they had identified 114 cases of kuru. There had been sixteen deaths among these and six more were pending. Samples of blood from these patients had been sent to the pathology laboratory in Port Moresby for analysis. No abnormalities were found, and there was no evidence of infection either from the blood results or tests for bacteria or viruses. None of the patients responded to any of a number of treatments tested for effect.
While collecting this information Zigas and Gajdusek had conducted autopsies on eight of their cases. Brain tissue from these had been preserved and sent for examination to neuropathologists in Washington, Adelaide, and Melbourne with the question ‘Is this a new disease?’ At the time their papers were published they had not received any response from the neuropathologists. They had to speculate about the possible causes of this disease. ‘Was it an environmental toxin or a nutritional deficiency?’ ‘Was it something introduced by Europeans?’ The latter seemed unlikely because of the very recent presence of outsiders in this remote region and the history of the disease among the Fore before their arrival. There was a possibility, too, that kuru was due to an inherited genetic fault.
The first publication on the pathology of the disease confirmed kuru as a disease of the cerebellum (part of the hindbrain). This paper was written by Australian pathologists. By 1959, Igor Klatzo from NIH had identified the changes in affected brains that are characteristic of kuru. He drew attention to the similarity of these to those seen in a relatively rare condition known as Creuzfeldt-Jakob disease (CJD).
In 1959 Gajdusek was visiting London and there he created a display about kuru, including its pathology, at the Wellcome Medical Museum. This display was seen by a veterinary pathologist from Montana, William Hadlow. Hadlow was familiar with a disease of sheep called scrapie and he saw that the changes in the brains of kuru patients were like those in scrapie. He also knew that scrapie was an infectious, transmissible disease. He quickly reported his belief in the similarity of the two diseases in a letter to the Lancet, a leading medical journal in the UK. For the first time, there was now a suggestion that kuru may, in fact, be due to an infective agent.
Gajdusek responded to this information by arranging the collection and dispatch to NIH of fresh and deeply frozen brain samples. These samples were provided by Michael Alpers, who had commenced his long association with research on kuru at about this time. He had done autopsies on patients he had followed throughout the course of their disease. He was able to do this with the support of the relatives of the victims. Deeply frozen samples from these brains travelled via Commonwealth Serum Laboratories in Melbourne to NIH. Here arrangements were made for inoculation of the brain tissue into the brains of chimpanzees. Alpers, who had gone to work at NIH, diagnosed clinical kuru in the first of these chimpanzees to become sick sixteen months after inoculation. He, Joe Gibbs and Elisabeth Beck autopsied the first chimpanzee to die of kuru. Elisabeth Beck confirmed that the pathology in this case was the same as that in human patients.
On hearing of the first results of the transmission experiment, Gajdusek returned to Washington from Okapa and he, Alpers and Joe Gibbs together wrote a paper for Nature claiming, for the first time, that kuru was caused by an infectious agent which Gajdusek called a ‘slow’ virus. Alpers, a medical graduate from Adelaide, had become involved with both kuru research and the Fore people since arriving in TPNG in 1961. He was the second director of the Papua New Guinea Institute of Medical Research and kept an interest in PNG affairs for sixty years. Alpers’ close association with the Fore people, like that of John Mathews and others involved in the investigation of kuru, made it much easier to collect the stories associated with the disease and to collect the information needed for their research.
The paper in Nature in 1966 drew international attention to PNG and its ‘new’ disease. Scientists in many institutions began to study the nature of Gajdusek’s ‘slow’ virus. By 1982 it had been discovered that it was not a virus at all, but a new form of infective agent that has been called a prion. It has also been found that prions are the cause of a well-defined group of diseases, all of which result in the brain damage characteristic of kuru. These diseases include scrapie of sheep, a disease of mink, mad cow disease and CJD. Before this new knowledge had been acquired Gajdusek’s original and sustained research into kuru was rewarded with the Nobel Prize in Medicine in 1976.
The question was eventually answered by medical scientists and anthropologists working closely with the Fore people. Robert and Shirley Glasse accumulated information in the early sixties about the funerary rites of the people in the Fore. This information, combined with all the medical and epidemiological data collected and published by Gajdusek, Zigas and Alpers and especially the results from the transmission experiments pointed clearly to the role of cannibalism in kuru. This complex process, described as transumption by Alpers, was a deeply embedded aspect of Fore culture. Body parts of victims of kuru, including the brains, were consumed by women as a mark of respect for the dead and to assist them on the journey to join their ancestors. Adult men did not participate in this custom; girls, women and boys below the age of initiation did. Gajdusek, by contrast, always contended that people were infected following the contamination of skin wounds and not by ingestion.
The role of these rites in transmission was strongly supported by the almost complete disappearance of kuru after the administration and missions succeeded in persuading the people to abandon this practice by the nineteen fifties. Sporadic cases, observed years afterwards, have been attributed by Alpers to their abnormally long incubation periods. Later experience with the cases of mad cow disease in people after eating the meat of affected cattle is additional evidence that prion infections like kuru can be acquired orally. The relatively early solution of the mad cow disease epidemic in Europe was one consequence of the preceding research on kuru.
I first heard of kuru, Carleton Gajdusek and Vin Zigas when I visited TPNG as a medical student in 1957. I returned to Port Moresby as Director of Pathology in the DPH in 1962, and served in this role for six years. Part of my work included ensuring that Gajdusek’s supplies for his research were sent on to him when he was working with the consent of the TPNG administration. I visited him in his laboratory in Washington in 1976, the year he received his Nobel Prize, and met him again at meetings around the world.
Because of a continuing interest in the story of kuru and its pathology, I have recently re-examined brain specimens held at the Maudsley Hospital in London where Elisabeth Beck had worked. Working with more modern techniques, one of their neuropathologists and I have been able, independently, to confirm Beck’s original findings. We were also able to demonstrate the presence of prions in these specimens—infective particles whose existence was unknown when the original work was done.
What has this done for medicine in PNG? It alerted the world to the fact that, like many aspects of its people and their culture, some diseases there were unique. Because of its importance to the health of the Fore people the research effort directed at it by people like Gajdusek and many others led to the identification of a new infective agent, the prion. A group of diseases of people and other animals became much better understood. All this put PNG, its people and their diseases on the map for world science.
In PNG, the effort directed at kuru illustrated the need for research into other diseases and resulted in the establishment of the Papua New Guinea Institute of Medical Research. That institute and medical practitioners in the country continue to investigate and gather information about the diseases affecting their people. It has been my privilege to meet and work with these people and to assist in studying the pathology of some of their disease problems.
Editor’s Note: Television channel SBS broadcast a program called ‘Kuru—the Science and the Sorcery’ in 2010. It is still accessible at SBS on Demand.
A vale for Carleton Gajdusek was published in Una Voce, March 2009. Images of Alpers and village scene courtesy of Michael Alpers.