While researching rabies last week I also happened upon quite a lot of sources dealing with Kuru, a neurological disease that, I must admit, has fascinated me for quite a while.
Kuru, also known as the laughing disease, has appeared numerous times in popular culture. People afflicted by kuru develop severe tremors in their limbs, which will eventually spread throughout the body, as well as developing depression, dementia, and emotional instability. Eventually the deterioration of the nervous system proves fatal. Below is a 1963 video of a Papua New Guinean woman who is infected with Kuru. The video, while silent, probably shouldn’t be watched at work due to slightly disturbing content and nudity.
Kuru is not caused by a viral or bacterial infection. Instead, similar to Creutzfeldt-Jakob disease (CJD), kuru is the result of an aberrant protein, a prion, which builds up in the brain. It spreads through the conversion of normal proteins into a disfigured form, making more of itself along the way. Part of the reason this disease has garnered so much attention is due to it’s similarities to mad cow disease (BSE), which scared many different countries into cattle purges.
The second reason why Kuru is popular in fiction is due to its odd method of transmission. Kuru was first discovered by western medicine during the 1950’s, as Australian scientists and supervisors ventured into the Eastern highlands of Papua New Guinea. It was endemic to the Fore people, a tribal group of people who practiced ritual cannibalism. When a person died, their remains were consumed by the tribe in order to return their life force to the village. The local women and children would prepare the body and eat the internal organs (including the brain) while the men got choicer cuts of meat.
Unfortunately, Kuru proteins can be spread both through ingestion and through contact with open wounds. Anyone who prepared a Kuru body or ate part of the brain was at risk of developing it. Thus the disease would spread in a cycle of infection-death-ritual-reinfection, hitting women and children most harshly. In some populations, this caused the ratio of men to women to become drastically unbalanced, to the point where an entire village may only have one or two healthy women left.
The ritual was stopped by the Australian medical researchers and doctors Daniel Carleton Gadjusek, Michael Alpers, and Baruch S. Blumberg. Since then kuru has mostly died off, however, it’s mark on popular culture remains strong. Perhaps it serves to reinforce our cultural taboo on cannibalism, a kind of deserved punishment for those who eat others. An odd vindication of our own cultural norms.
Michael Alpers has recently produced a film known as Kuru: a medical detective story in 2010. The trailer can be seen here. I also recommend watching the accompanying Q&A session on Youtube.
Sources: PubMed, Youtube, Wikipedia.