Ulcerative colitis in the Kinneret sub district, Israel 1965-1994: incidence and prevalence in different subgroups.

Ulcerative colitis (UC) is prevalent among Jews around the world, as well as in Israel. We evaluated the incidence rates of the disease in one of the northern districts of Israel (Kinneret) by religion and by type of settlement. The population in this district is composed of Jews who have immigrated to Israel in the last century from various countries all over the world, and from Arabs. The study population included all residents of Kinneret district diagnosed with UC between 1965 and 1994. The mean annual incidence rate of UC in the 30 years covered in this survey (1965-1994) proved to be 3.5/100,000. A trend of increase in the incidence rate was observed until 1989. It was most prominent among the Jewish rural settlements. Since 1989, the rates have been declining. Prevalence rates were 87/100,000 among the Jewish population, and 27/100,000 among the Arab population. Both prevalence and incidence rates were 2.5 times higher among Jews than among Arabs. We include that (1) UC morbidity had been increasing until 1989 and has been decreasing moderately ever since; (2) the lowest morbidity was found in the Arab population; and (3) the highest morbidity was found among the Jewish rural population.