prion disease
Julie Hambleton
Julie Hambleton
June 17, 2024 ·  3 min read

Kuru: The World’s deadliest disease with a near 100% fatality rate

In the realm of rare and debilitating illnesses, one disease stands out as particularly sinister: Kuru. This devastating condition is also known as a brain-eating disease. Though it does sound very scary, it is incredibly rare. This is everything you should know about Kuru disease.

Kuru: The World’s Deadliest Disease with a Near 100% Fatality Rate

Kuru is categorized as a prion disease. It has a notorious reputation due to its near 100% fatality rate. As awareness surrounding Kuru has increased, its occurrence has become essentially non-existent. Primarily, it was confined to specific regions, such as New Guinea. But what is a prion disease, and how does one even contract a disease like this? Let’s delve into the intricacies of prion diseases, explore the different types of prion diseases, and get a better understanding of Kuru: its origins, transmission, and its decline in recent years. (1)

What Are Prion Diseases?

Prion diseases, also known as transmissible spongiform encephalopathies (TSEs), are a group of rare and fatal disorders affecting humans and animals. Unlike typical infectious diseases caused by bacteria or viruses, prion diseases are caused by misfolded proteins called prions. These prions induce abnormal folding in normal proteins, leading to a cascade of neurological degradation. These diseases are characterized by long incubation periods ranging from months to several years, followed by a rapid decline in cognitive and physical functions.

Types of Prion Diseases

Apart from Kuru, there are five other well-known prion diseases. These include:

  • Creutzfeldt-Jakob Disease (CJD)
  • variant Creutzfeldt-Jakob Disease (vCJD)
  • fatal familial insomnia (FFI)
  • Gerstmann-Sträussler-Scheinker syndrome (GSS)
  • sporadic fatal insomnia (sFI)

Each disease varies in terms of symptoms, onset, and transmission. Creutzfeldt-Jakob Disease (CJD) is the most common type of prion disease, accounting for at least 85% of all cases. CJD can be sporadic, meaning it occurs randomly in individuals with no family history of the condition or hereditary, which means it’s passed down through families.

Understanding Kuru Disease

Kuru disease, known locally as “the laughing sickness,” was first discovered among the Fore people of Papua New Guinea in the 1950s. It primarily affected women and children within specific communities, leading to its identification as a distinct prion disease. The transmission of Kuru occurs through the ritualistic cannibalization of deceased individuals. Anthropological studies revealed that the Fore people performed cannibalistic funerary practices, including consuming the brains of deceased family members. These practices exposed individuals to infectious prions, causing the development of Kuru. (2)

Transmission and Prevalence

Due to the specific cultural practices involved in its transmission, Kuru remained localized within the Fore population for many years. The disease was primarily spread by ingesting infected brain tissue containing abnormal prions. Symptoms of Kuru include tremors, unsteady gait, muscle stiffness, and eventually progressive dementia, leading to death within a year of the onset of symptoms.

Decline of Kuru

In the 1950s, scientists and medical professionals discovered the link between Kuru and its mode of transmission. As awareness and understanding of Kuru grew, efforts were made to discourage and abolish cannibalistic practices, leading to a significant decline in the disease. Additionally, in 1957, the Australian government imposed a ban on cannibalism in affected regions of Papua New Guinea, further curbing the spread of the disease. These combined measures and improvements in healthcare and education have led to a remarkable reduction in the incidence of Kuru. The disease is considered extremely rare and no longer a public health concern in New Guinea.

The Bottom Line

Kuru, the world’s deadliest disease with a near 100% fatality rate, is not something you have to be concerned about. It belongs to the group of prion diseases but is only transmitted through cannibalistic practices. Once prevalent among the Fore people in New Guinea, it is essentially eradicated now. With increased awareness and successful interventions, the occurrence of Kuru has significantly declined to essentially zero. Although the risk of exposure to prion diseases still exists, the decline of Kuru serves as a testament to the power of public health initiatives and the potential for eradicating even the most devastating diseases.

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  1. Prion Diseases.” Hopkins Medicine
  2. Kuru.” NCBI. Sanjay Mahat and Ria Monica D. Asuncion. May 29, 2023.