Creutzfeldt-jakob disease: focus among Libyan Jews in Israel.

A countrywide search for Creutzfeldt-Jakob disease in Israel disclosed 29 cases with onset between 1963 and 1972. Incidence in various ethnic groups varied in the narrow range of 0.4 to 1.9 per million population except among Jewish immigrants from Libya, among whom the incidence was 31.3 per million. An extraordinary excess of Creutzfeldt-Jakob disease exists in this ethnic group.