Kuru (disease)

Kuru
A Fore child with advanced kuru. He is unable to walk or sit upright without assistance and is severely malnourished.
Pronunciation	IPA: kuru
Specialty	Neuropathology, infectious disease
Symptoms	Body tremors, random outbursts of laughter, gradual loss of coordination
Complications	Infection and pneumonia during the terminal stage.
Usual onset	Often takes years or even decades for symptoms to appear after exposure
Duration	11–14 month life expectancy after onset of symptoms[1]
Causes	Transmission of infected prion proteins
Risk factors	Cannibalism
Diagnostic method	Autopsy
Differential diagnosis	Creutzfeldt–Jakob disease
Prevention	Avoiding practices of cannibalism
Treatment	Supportive care
Prognosis	Fatal
Frequency	Rare
Deaths	Approximately 2,700 as of 2005

Kuru is a rare, incurable, and fatal neurodegenerative disorder that was formerly common among the Fore people of Papua New Guinea. Kuru is a form of transmissible spongiform encephalopathy (TSE) caused by the transmission of abnormally folded proteins (prions), which leads to symptoms such as tremors and loss of coordination from neurodegeneration.

The term kuru derives from the Fore word kuria or guria ("to shake"),^[2] due to the body tremors that are a classic symptom of the disease. Kúru itself means "trembling".^[3] It is also known as the "laughing sickness" due to the pathologic bursts of laughter which are a symptom of the disease. It is now widely accepted that kuru was transmitted among members of the Fore tribe of Papua New Guinea via funerary cannibalism. Deceased family members were traditionally cooked and eaten, which was thought to help free the spirit of the dead.^[4] Women and children usually consumed the brain, the organ in which infectious prions were most concentrated, thus allowing for transmission of kuru. The disease was therefore more prevalent among women and children.

The epidemic likely started when a villager developed sporadic Creutzfeldt–Jakob disease and died. When villagers ate the brain, they contracted the disease and then spread it to other villagers who ate their infected brains.^[5]

While the Fore people stopped consuming human meat in the early 1960s, when it was first speculated to be transmitted via endocannibalism, the disease lingered due to kuru's long incubation period of anywhere from 10 to over 50 years.^[6] The epidemic finally declined sharply after half a century, from 200 deaths per year in 1957 to no deaths from at least 2010 onwards, with sources disagreeing on whether the last known kuru victim died in 2005 or 2009.^{[7][8][9][10]}