Daniel Carleton Gajdusek was a complex figure in biomedical research. His career involved pioneering scientific discoveries that reshaped understanding of infectious diseases, but was marked by personal controversy. His work with remote populations illuminated unknown disease mechanisms, leaving a multifaceted legacy.
Unraveling Kuru and Transmissible Diseases
Gajdusek’s most recognized contributions involved Kuru, a devastating neurodegenerative disorder affecting the Fore people of Papua New Guinea. Kuru, locally known as “to tremble” or “laughing sickness,” caused progressive tremors, loss of muscle control, mental decline, and typically led to death within three months. In 1957, Gajdusek, with Vincent Zigas and Shirley Lindenbaum, began studying the disease within the Fore community.
Kuru predominantly affected Fore women and children, sparing adult males. This led Gajdusek to hypothesize a transmission route linked to funerary practices. The Fore engaged in ritualistic endocannibalism, consuming deceased relatives’ bodies, especially the brain, as an act of mourning. Women and children often consumed the brain tissue, which contained the infectious agent, linking this custom to the disease’s spread.
To validate this, Gajdusek conducted experiments at the National Institutes of Health. He inoculated chimpanzees with brain tissue from Kuru victims. After a long incubation (months to years), chimpanzees developed symptoms mirroring human Kuru, demonstrating cross-species transmissibility. This experimental transmission, with collaborators Michael Alpers and Joe Gibbs, provided evidence for an infectious agent.
Gajdusek described this agent as an “unconventional” or “slow” virus due to its prolonged incubation and lack of typical inflammatory or immune responses. This challenged prevailing notions of infectious diseases, suggesting a novel class of pathogens. Subsequent research, by Stanley Prusiner, identified these agents as prions—misfolded proteins (PrPSc) capable of inducing normal proteins to misfold. These misfolded proteins accumulate, causing sponge-like holes in brain tissue seen in Kuru and other transmissible spongiform encephalopathies (TSEs).
Nobel Recognition and Broader Scientific Impact
Kuru research earned him international acclaim. In 1976, he shared the Nobel Prize in Physiology or Medicine with Baruch S. Blumberg. The prize recognized their discoveries concerning “new mechanisms for the origin and dissemination of infectious diseases,” highlighting Kuru’s transmissibility.
Kuru findings provided insights for understanding other neurodegenerative conditions. It established the concept of an infectious agent with a long incubation period causing progressive brain degeneration. This work influenced research into other human TSEs, such as Creutzfeldt-Jakob Disease (CJD), a rapidly progressive and fatal neurological disorder.
Understanding from Kuru extended to animal diseases like Bovine Spongiform Encephalopathy (BSE), or “Mad Cow Disease,” and scrapie in sheep. The idea that a misfolded protein, not a conventional microorganism, could be an infectious agent influenced neurobiology. This paradigm shift provided a framework for investigating protein misfolding and aggregation, now recognized as underlying processes in common neurodegenerative diseases, including Alzheimer’s and Parkinson’s.
Controversy and His Final Years
Despite his scientific achievements, Gajdusek’s later life was overshadowed by controversy. In April 1996, he was charged with child molestation. Allegations stemmed from an investigation uncovering incriminating entries in his diaries and journals, and victim testimony.
Gajdusek brought dozens of children, primarily boys, from the South Pacific (Micronesia, Papua New Guinea) to live with him, providing educational opportunities. In 1997, he pleaded guilty to child abuse, accepting a plea bargain for a twelve-month prison sentence. This conviction tarnished his public and scientific reputation.
After his 1998 prison release, Gajdusek left the United States, living in self-imposed exile in Europe. He continued scientific pursuits, residing in Amsterdam, Paris, and Tromsø, Norway. Daniel Carleton Gajdusek died in Tromsø on December 12, 2008, at 85, ending a life marked by scientific breakthroughs and personal failings.