The association between childhood environmental exposures and the subsequent development of Crohn's Disease in the Western Cape, South Africa

Basson, Abigail; Swart, Rina; Jordaan, Esme; Mazinu, Mikateko; Watermeyer, Gillian

The association between childhood environmental exposures and the subsequent development of Crohn's Disease in the Western Cape, South Africa

Journal Article

2014

Journal Title

PLoS One

Link to Journal

http://journals.plos.org/plosone

Publisher

Public Library of Science

Publisher

University of Cape Town

Department

Division of Surgical Gastroenterology

Faculty

Faculty of Health Sciences

License

http://creativecommons.org/licenses/by/4.0

Abstract

BACKGROUND: Environmental factors during childhood are thought to play a role in the aetiolgy of Crohn's Disease (CD). However the association between age at time of exposure and the subsequent development of CD in South Africa is unknown. METHODS: A case control study of all consecutive CD patients seen at 2 large inflammatory bowel disease (IBD) referral centers in the Western Cape, South Africa between September 2011 and January 2013 was performed. Numerous environmental exposures during 3 age intervals; 0-5, 6-10 and 11-18 years were extracted using an investigator administered questionnaire. An agreement analysis was performed to determine the reliability of questionnaire data for all the relevant variables. RESULTS: This study included 194 CD patients and 213 controls. On multiple logistic regression analysis, a number of childhood environmental exposures during the 3 age interval were significantly associated with the risk of developing CD. During the age interval 6-10 years, never having had consumed unpasteurized milk (OR = 5.84; 95% CI, 2.73-13.53) and never having a donkey, horse, sheep or cow on the property (OR = 2.48; 95% CI, 1.09-5.98) significantly increased the risk of developing future CD. During the age interval 11-18 years, an independent risk-association was identified for; never having consumed unpasteurized milk (OR = 2.60; 95% CI, 1.17-6.10) and second-hand cigarette smoke exposure (OR = 1.93; 95% CI, 1.13-3.35). CONCLUSION: This study demonstrates that both limited microbial exposures and exposure to second-hand cigarette smoke during childhood is associated with future development of CD.