Epidemiology of Crohn's disease in the Jewish population of central Israel, 1970-1980.

The epidemiology of Crohn's disease (CD) during the years 1970-80 was studied in the Jewish population in a defined area of central Israel with 1.4 million inhabitants. Three hundred sixty-five patients with definite CD were identified, and a complete follow-up was obtained. The incidence of CD rose from 0.33 (per 10(5)) in 1970 to 3.10 in 1979. This rise was noted in both sexes, in all age groups, in all major Jewish community groups, and was demonstrated in three different regions of the study area. It is thought to represent a true (10-fold) increase in incidence. The mean annual incidence was 1.55/10(5). The prevalence in 1970 was 7.08/10(5), and in 1980 it was 19.47/10(5). In 1970, the age-adjusted prevalence in immigrants from Europe-America was 13.27 and in immigrants from Asia-Africa it was 1.69. In 1980, the difference between the two groups narrowed and the prevalences were 26.05 and 12.37, respectively. This decrease in differences between original migrant groups, as well as the rapid changes in incidence, point to the effect of environmental factors in the pathogenesis of CD. Population studies worldwide have demonstrated an increased incidence of CD in Jews, with marked differences among Jews in different geographic areas. This suggests the coexistence of genetic and environmental factors in the pathogenesis of the disease.