By Richard P. Holm MD
50 years ago in the highlands of New Guinea, a strange neurodegenerative epidemic began to occur among one tribe. This particular native society was being devastated by a condition they called “kuru”, which in their language means “to shiver or shake”. People affected by kuru would start showing symptoms of an unsteady gait, tremors, and slurred speech. Although dementia was minimal, kuru would cause mood changes and eventually result in an inability to stand or eat. The victims of this disease would die in a coma about 12 months after gait changes started.
As medical science analyzed this condition, it was discovered that kuru was caused by an infectious virus-like prion—a misfolded protein—which causes other protein molecules to become misshapen, clump, and accumulate in the brain. Kuru characteristically concentrates in the cerebellum, which is the balance and coordination center of the brain. The macabre turn to this story came when scientists discovered kuru was spread as a result of the rather gruesome practice of ritualistic cannibalism practiced by this remote tribe. Recently deceased beloved relatives would be prepared and consumed, especially the brains, in a ceremony to honor the dead; thus the infection would spread.
Kuru, like several other brain prion diseases, causes neurological symptoms which can occur months or even decades after transmission of the infection, making the diagnosis difficult. Other examples of this kind of brain infection include Creutzfeldt-Jakob disease in humans, mad cow disease in cattle, scrapie in sheep, and chronic wasting disease in deer and elk. Although this kind of protein-changing infection cannot be transmitted through the air or by casual contact, it can be transmitted by consumption of infected tissue or bodily fluids.
One should not jump to the conclusion that other neurodegenerative diseases like Alzheimer’s or Parkinson’s are due to a prion infection like kuru. However, there are protein changes and clumping noted in these brains too, giving one pause to consider that there could be some sort of infectious relationship to these neurological conditions as well. The research goes on.
With a great deal of effort and local governmental intervention, the people of that tribe in New Guinea were convinced to no longer consume their recently dead relatives, and kuru has mostly disappeared. Ritualistic cannibalism may be gone, but other prion-infections of the brain are not. It is through careful scientific research and work that we have hope.