Descriptive epidemiology of Creutzfeldt-Jakob disease in Finland.

In 1974-84 30 patients died with a diagnosis of Creutzfeldt-Jakob disease (CJD) in Finland. Sixteen of the patients were pathologically confirmed and 14 were probable cases; 6 were familial (20%). One further familial patient was alive at the end of 1984. The median age of the 30 patients at death was 59.5 years (range 46-73 years). The familial patients were significantly younger than sporadic cases (median and range 49.5 and 46-57 versus 61.5 and 51-73; P less than 0.01). Only 5 of the 24 sporadic patients were men (male to female ratio 1:3.8). The annual number of new cases as well as the death rate increased in the late 1970's (annual death rate 0.57 per million in 1974-84 and 0.91 in 1979-84). This probably reflects the growing awareness of CJD among neurologists, rather than a real increase of the incidence and death rate. Annual age-specific death rate per 1 million population in 1974-84 reached a peak value of 2.57 in the age group of 60-64 years. In sporadic CJD the age-specific death rate of women was higher than that of men in all age groups. A chronic medical condition, precedent or concomitant with CJD, was seen in 15 patients.