Kuru is a degenerative nerve disease caused by a prion (infectious protein) transmitted to humans via contaminated human brain tissue.

Causes, incidence, and risk factors

Kuru is an extremely rare prion disease. It is almost exclusively found among people from New Guinea, who practiced a form of cannibalism in which the brains of dead relatives were eaten as part of a funeral ritual. Kuru causes neurodegenerative changes similar to another prion disease, Creutzfeldt-Jakob disease, which occurs sporadically around the world and for which risk factors are unknown.

In addition, similar prion diseases appear in sheep as scrapie, mink as encephalopathy, and in cows as bovine spongiform encephalopathy (BSE) (“mad cow disease”). The main risk factor for the development of kuru is eating human brain tissue, which can contain the infectious particles.

Kuru may begin with difficulty walking and increasing incoordination, which eventually become severe. Tremors and muscle jerks are often seen in the later stages of the disease. Difficulty swallowing and inability to feed oneself lead to malnutrition or starvation.

The incubation period (the time it takes until symptoms develop) for this disease can be up to 30 years or longer. Death, however, usually occurs within a year after the onset of symptoms.


  • Difficulty walking (cerebellar ataxia)  
  • Incoordination  
  • Swallowing difficulty

Signs and tests
A neurologic evaluation may show characteristic changes in coordination and gait in someone who may have been exposed to the disease.

No treatment is currently available for kuru or any of the prion diseases.

Expectations (prognosis)
Kuru is universally fatal.

Calling your health care provider
Call your health care provider if you have any gait disturbance, swallowing difficulty, or incoordination. Although kuru is extremely rare (less than 10 cases per year are diagnosed in the world), other severe neurologic disorders can cause these symptoms and should be evaluated.

The risk of kuru has diminished considerably with the discontinuation of cannibalism and ritualistic practices that expose humans to infectious brain tissue.

Johns Hopkins patient information

Last revised: December 3, 2012
by Martin A. Harms, M.D.

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