by D. Vogt

Created on: August 13, 2010

Kuru, also known as laughing sickness, is a neurological disease which existed among the Fore people of Papua New Guinea. It is a spongiform encephalopathy, the same sort of grave condition caused by Creutzfeldt-Jakob disease and mad cow disease.

Spongiform encephalopathies are extremely serious but fortunately rare brain diseases caused by malformed proteins, called prions. They cause holes to appear and spread in the brain, resulting in a porous or sponge-like appearance to the tissue. Prions are unlike viruses or bacteria, which cause most contagious diseases. They are proteins which have become damaged, or misshapen, and which cause serious brain problems. Currently, there is no ability to treat or cure these diseases, including kuru.

In the case of kuru, anthropologists and medical doctors first became aware of the spread of a new and unidentifiable disease among the Fore in the 1950s. The Fore themselves had been experiencing the condition for decades, although the arrival of new colonial administrators coincided with a large increase in the frequency of the disease. Those who were afflicted suffered from headaches, pain, and tremors, as well as bouts of uncontrollable laughter. By the time the Australian professionals became aware of the problem, however, the condition was already widespread in the Fore and nearby groups, reaching epidemic levels.

Eventually, the cause and full course of the disease was identified by a combination of medical and anthropological research. The Fore participated in a traditional religious ritual in which parts of the body, including the brain, were removed after death and eaten by relatives. At some point, the first mutated prions appeared in one member of the population. From there, they spread to others who ate parts of his or her body. (It is also possible that the prions could have spread through contaminated wounds during the rituals, but from what we know about how mad cow disease can also spread, eating the brain seems to be the most likely vector of transmission.) By the 1960s, over one thousand people were known to have died of the disease.

In the 1960s, more as a result of missionary influence and concern over aboriginal ritual than over the specific problem of Kuru, the government of Australia (which was then responsible for administering Papua New Guinea, until its independence in 1973) outlawed all cannibalism on the islands. The cannibalistic practices among the Fore then ceased. As a result, the outbreaks of new cases of laughing sickness dropped as well. However, further research identified an incubation period which could stretch into decades. As a result, elderly Fore still develop the final, fatal, symptomatic stage of the disease at the rate of around one case per year. The frequency continues to tail off and should eventually cease entirely.

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