Prevalence and incidence of IBD in Sri Lanka

Abstract

Recent reports indicate an increase in Inflammatory Bowel Disease (IBD) in Asia. However, there are few robust epidemiological studies based on prospective data from hospitals with defined catchment areas from the region. There are two epidemiological studies on IBD from Sri Lanka. One was a cross sectional hospital-based survey from Dec. 2007–Nov. 2008 in the Colombo and Gampaha districts. Case detection was based on in-ward, out-patient, endoscopy and histology records. 295 IBD cases (UC=240, CD=55) were identified; crude prevalence rates were: UC 5.3/100,000 population (95%CI 5.0-5.6), CD 1.2/100,000 population (95%CI 1.0-1.4). Female:Male was 1.5 for UC, 1.0 for CD. Ethnicity reflected the districts’ demography. Mean age at diagnosis (males and females) was 36.6 and 38.1 years for UC; 33.4 and 36.2 years for CD. There was a bi-modal age distribution. Among UC patients, 51.1% had proctitis, and 58.4% had mild disease at presentation. 80% CD patients had only large bowel involvement. Only 2.2% UC and 5.5% CD patients had a positive family history. The second study was a prospective, population-based incidence study in Gampaha District. Hospitals in Gampaha District and in the adjoining areas of Colombo District were kept under surveillance for one year from April 2011. 35 IBD (UC=21, CD=13, IC=1) cases were detected: crude annual incidence of IBD 1.6/100,000 population (95%CI: 1.1-2.2); UC 1/100,000 (95%CI: 0.6-1.5), M:F=8:14; median age at diagnosis 34.8y; CD 0.6/100,000 (95%CI: 0.3-1.0), M:F=8:6; median age at diagnosis 36.8y. There seemed to be more CD in younger age groups. A family history of IBD was reported by 2 (5.7%) patients. Rates of IBD were low compared to the West, but were comparable to reports from many other Asian countries. The female predominance for UC contrasts with many reports. There were low rates in children, with less familial clustering.