Kuru is an extremely rare and fatal nervous system disease. The disease reached its peak during the 1950s and 1960s among the Fore people in the highlands of New Guinea. The Fore people contracted the disease by performing cannibalism during funeral rituals.
Kuru is characterized by difficulty walking, swallowing, and chewing. Symptoms also include loss of coordination and muscle twitching.
The name kuru translates to “shiver” or “trembling in fear.” Kuru has no known cure and is generally fatal within one year.
You can contract the disease by eating an infected brain or coming into contact with open wounds or sores. Kuru developed from the people of New Guinea eating brains of dead relatives during funeral rites. Women and children were of the majority infected with kuru. This is because they were the primary participants in the funerary rituals.
The New Guinea government has discouraged the practice of cannibalism. However, the disease has a long incubation period. Therefore, occasional cases still appear in very rare instances.
Infectious, abnormal proteins known as prions cause Kuru. Prions bind together to form lumps in the brain. According to the National Institute of Neurological Disorders and Stroke, scientists believe that healthy proteins mimic the abnormal shape of prions (NINDS, 2011).
Creutzfeldt–Jakob (C-J) and fatal familial insomnia are other degenerative diseases caused by prions. These diseases (as well as Kuru) are spongiform disease. All spongiform diseases cause sponge-like holes in the brain and are fatal.
According to the University of Utah (UT), C-J disease is the most common of the spongiform diseases (UT, 2012). Even so, C-J disease only occurs in one in one million people. Researched believe that variant C-J disease is related to mad cow disease.
Symptoms of more common neurological disorders (such as Parkinson’s disease or stroke) may resemble kuru. Symptoms include:
- trouble walking
- increasingly poor coordination
- difficulty swallowing
- slurred speech
- muscle twitching and tremors
- pain in the legs and arms
- random laughing and/or crying
Malnutrition and starvation follow initial symptoms because those infected with kuru have difficulty eating and swallowing. These secondary symptoms can lead to death within a year.
A doctor will perform a neurological exam to diagnose kuru. This is a comprehensive medical examination. It includes your medical history, neurological function, and blood tests. Examples of blood tests used include thyroid, folic acid level, and liver and kidney function tests.
The exam may also include electrodiagnostic tests. These tests include electromyography (EMG) or nerve conduction velocity (NCV). These tests examine the electrical activity in your brain. Brain scans such as an MRI may be necessary as well.
The incubation period (the time between initial infection and the appearance of symptoms) of kuru can be as long as 30 years. Therefore, cases have been reported long after the practice of cannibalism has ceased.
Kuru is very rarely diagnosed. Kuru symptoms more likely indicate another serious neurological disorder or spongiform disease.
There is no known successful treatment for kuru. According to the University of Utah, boiling water, radiation, and acid cannot destroy the prions that cause kuru (UT, 2012). Brains contaminated with prions remain infectious even when preserved in formaldehyde for years.
Individuals with kuru require assistance to stand and move, eventually losing the ability to swallow and eat. According to the National Center for Biotechnology Information, people infected with kuru die in a comatose state within six to 12 months after experiencing initial symptoms (NCBI, 2010).
Kuru is exceptionally rare. It is only contracted by ingesting infected brain tissue or coming into contact with sores infected with prions. Kuru prevention hinged on government’s and society’s discouragement of cannibalism during the kuru epidemic of the mid-20th century. According to NINDS, the disease has almost completely vanished (NINDS, 2011).