Kuru was a rare brain disease that was discovered in Papua New Guinea. It first came to medical attention in the 1950s when colonial health officers and local physicians noticed an unusual syndrome affecting women and children in the Fore speaking area of PNG’s Eastern Highlands. People with kuru often first developed shaking, difficulty walking, and loss of balance. As the disease advanced, they could no longer control their movements and also showed changes in mood and behavior. One unusual sign was sudden, uncontrollable laughter. Eventually, the disease led to coma and death.
Children with Kuru in Papua New Guinea.
When doctors studied the brains of people who died from kuru, they found that the brain tissue had developed tiny holes, making it look like a sponge, and contained unusual clumps of protein. Later, scientists discovered that the illness was caused by prions; a type of protein that becomes misshapen and then causes other normal proteins in the brain to misfold as well. Transmission historically occurred within communities through the ritual practice of consuming the tissues ,especially brain of deceased relatives during mortuary feasts (a practice often called transumption).
Fore people of Papua New Guinea.
Daniel Carleton Gajdusek (United States) carried out experiments that proved transmissibility of kuru by transmitting disease to chimpanzees using brain material from kuru patients. These transmission experiments provided the crucial evidence that kuru was caused by an infectious agent rather than by genetics or other non-infectious causes. For this and related work on “slow” infectious diseases, Gajdusek was awarded the Nobel Prize in Physiology or Medicine in 1976. The Nobel committee specifically cited his work on the origin and dissemination of unusual human diseases such as kuru.
Dr Daniel Carleton Gajdusek receiving the Noble prize in 1976.
Michael P. Alpers (Australia/PNG), who worked extensively in PNG over decades, performed sustained epidemiological and field research that documented kuru’s geographic distribution, demographic patterns, decline after cessation of mortuary cannibalism, and the very long incubation periods that characterize human prion diseases. Alpers’ careful field epidemiology and partnership with PNG communities and clinicians were essential in defining kuru’s natural history; he later served as Director of the PNG Institute of Medical Research and received multiple honours for his contributions to tropical medicine and PNG health (including election as a Fellow of the Royal Society).
Professor Micheal P Alpers
Subsequent work by other scientists notably Stanley B. Prusiner, whose work in the 1980s and 1990s characterized the infectious agent as a misfolded host protein (“prion”) completed the molecular understanding of kuru’s cause. Prusiner then received the Nobel Prize in Physiology or Medicine in 1997 for the prion concept, which integrated and extended insights gained from kuru and related diseases.
Kuru was the first human disease shown to be transmissible by brain tissue in experimental animals, which helped establish a new category of diseases — prion diseases or transmissible spongiform encephalopathies — that include scrapie (sheep), Creutzfeldt-Jakob disease (humans), and bovine spongiform encephalopathy (BSE) in cattle. The kuru data were essential empirical pillars for the prion hypothesis.
Today, kuru is considered to have disappeared as a disease. The cultural practice of transumption that once spread the illness was abandoned in the mid-20th century, halting further transmission. Although a few cases continued to appear for decades due to the exceptionally long incubation period of prion diseases, the last known patients were reported in the early 2000s. No new cases have since been identified, and kuru is no longer a public health concern. Nonetheless, its legacy is profound, the study of kuru reshaped medical understanding of prion diseases and provided crucial insights into neurodegeneration, infectious proteins, and human cultural practices that influence health.
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