Incidence and prevalence of Crohn’s disease and its etiological influences

Epidemiologic studies are of paramount importance in investigating disease etiology. Medical literature for individual countries on the incidence of CD, were retrieved from published medical literature and reports from relevant international congresses. Increasing trends have been observed almost worldwide, with a broad north–south gradient still prevailing in Europe. Distinct regions of New Zealand, Canada, Scotland, France, the Netherlands, and Scandinavia represent the highest incidence areas. Industrialized status and affluence are the common denominators between endemic areas, but are too broad terms to strongly indicate any particular etiological role. The increasing trends observed in Asia still account for a low prevalence of the disease and may represent increased detection and diagnostic ability of local health systems.