Kuru: A Review of a Rare Human Prion Disease

Abstract

The kuru outbreak persisted for nearly one hundred years. It first appeared around 1901–1902,became a widespread epidemic in the middle of the 1950s and eventually disappeared in the 1990s. It is acknowledged as first known case of a group of neurological conditions called prion diseases, or ‘transmissible spongiform encephalopathies (TSEs)’. Scientific knowledge of Kuru has advanced due to developments in studies on the genetics as well as biological mechanisms of TSEs, while findings from the kuru epidemic itself have played a crucial role in understanding how variant Creutzfeldt-Jakob disease continues to spread throughout Europe. This review's main goal is to draw attention to and clarify these reciprocal contributions. The highly restricted marriage customs of the affected communities, combined with their geographic and social isolation, would have made the spread of a newly arisen genetic mutation extremely slow. Such a mutation could only have become widespread if it had existed in the original ancestors of a founding population from which the core groups later affected by kuru descended, prior to the development of near-complete marital isolation among hamlets. Although environmental influences and the potential roles of infectious agents, toxins, or nutritional deficiencies—either independently or interacting with genetic susceptibility—have not been entirely ruled out, current research has focused mainly on biochemical studies.
In particular, investigations into intermediary metabolism among individuals with kuru and unaffected members of the same population, some of whom later developed the disease, form the central approach. These biochemical studies are expected to deepen understanding of the causes and disease mechanisms of kuru, regardless of whether its origin is purely genetic or involves additional contributing factors.