Review. The epidemiology of kuru: monitoring the epidemic from its peak to its end.

Kuru is a fatal transmissible spongiform encephalopathy restricted to the Fore people and their neighbours in a remote region of the Eastern Highlands of Papua New Guinea. When first investigated in 1957 it was found to be present in epidemic proportions, with approximately 1000 deaths in the first 5 years, 1957-1961. The changing epidemiological patterns and other significant findings such as the transmissibility of kuru are described in their historical progression. Monitoring the progress of the epidemic has been carried out by epidemiological surveillance in the field for 50 years. From its peak, the number of deaths from kuru declined to 2 in the last 5 years, indicating that the epidemic is approaching its end. The mode of transmission of the prion agent of kuru was the local mortuary practice of transumption. The prohibition of this practice in the 1950s led to the decline in the epidemic, which has been prolonged into the present century by incubation periods that may exceed 50 years. Currently, the epidemiological surveillance is being maintained and further studies on human genetics and the past mortuary practices are being conducted in the kuru-affected region and in communities beyond it.