EPIDEMIOLOGY OF CREUTZFELDT-JAKOB-DISEASE

Creutzfeldt-Jakob disease is a rare disease (incidence < 1 case per mi llion inhabitants), reported in all continents. Certain characteristic s are constant from one country to another: mean age of onset: 65 year s, duration of the disease: about 6 months, sex ratio close to I and a pproximately 10% of familial cases. The geographical sites of this dis ease identified in Chile, Israel and Czechoslovakia suggest certain ge netic and/or environmental risk factors. The principal environmental f actor implicated is scrapie in sheep, especially in these regions. Gen etic studies have demonstrated the presence of apparently causal mutat ions of the PrP gene and a high risk of CJD associated with certain no rmal polymorphisms of this gene (codon 129). Certain grafts (dura mate r, corneal and treatment by extracted growth hormone are responsible f or iatrogenic transmission. Multicentre epidemiological studies recrui ting a large number of cases are needed to define the risk factors of this disease.