Kuru among the Fore

In the language of the Fore people of Papua New Guinea's Eastern Highlands, kuru means to tremble from fever or cold. The disease was confined to the Fore and neighboring language groups. By Fore accounts it first appeared around 1900 in a Keiagana village to the northwest and reached the central South Fore by 1930. Patients trembled and grew steadily more unsteady, and died about a year after the first signs. Some showed inappropriate euphoria and compulsive laughter. In 1955 Vincent Zigas at Kainantu, the government station, provisionally diagnosed a typical case as acute hysteria.

Patrol officers had described kuru from 1953, and Zigas and D. Carleton Gajdusek first reported it in medical journals in two 1957 papers. It was epidemic, with about 1,000 deaths across the kuru region from 1957 to 1961. Among some 12,000 Fore, the death rate in some villages approached 35 per 1,000. Of the cases in 1957 to 1959, 60 percent were adult women and only 2 percent adult men; the rest were children and adolescents of both sexes.

On 21 July 1959 Gajdusek, then in New Guinea, received a letter from William Hadlow, an American veterinary pathologist at the Rocky Mountain Laboratory in Montana. Hadlow pointed out how closely kuru resembled scrapie, a slow brain disease of sheep and goats that could be passed between animals after very long incubation. Chimpanzees were inoculated with brain tissue taken from patients soon after death. After about two years they showed changes in behavior and then unmistakable cerebellar ataxia, and the transmission was reported in 1966.

The anthropologists Robert Glasse and Shirley Lindenbaum were the first to propose that kuru spread through the mortuary practice in which the Fore ate their dead relatives, and women took part in many such feasts. The Australian administration had banned the practice. Public feasting stopped by the mid-1950s, the practice was abandoned by the early 1960s, and in the South Fore almost no child born after 1954 developed kuru. Gajdusek shared the 1976 Nobel Prize in Physiology or Medicine for discoveries on new mechanisms for the origin and spread of infectious diseases. Deaths fell to two in the five years before 2008, and some incubation periods may have exceeded 50 years.