Systematic Reviews
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 21, 2019; 25(47): 6866-6875
Published online Dec 21, 2019. doi: 10.3748/wjg.v25.i47.6866
Epidemiology of inflammatory bowel disease in South America: A systematic review
Sriharan Selvaratnam, Santiago Gullino, Lisa Shim, Eric Lee, Alice Lee, Sudarshan Paramsothy, Rupert W Leong
Sriharan Selvaratnam, Santiago Gullino, Lisa Shim, Eric Lee, Alice Lee, Sudarshan Paramsothy, Rupert W Leong, Department of Gastroenterology and Hepatology, Macquarie University Hospital, Sydney 2109, New South Wales, Australia
Author contributions: Selvaratnam S, Gullino S and Leong RW contributed to the conception and design of the study; Selvaratnam S conducted the systematic review, data extraction and manuscript production; Gullino S assisted with independent review of search results; Shim L, Lee E, Lee A, Paramsothy S and Leong RW provided expert opinion and approved the final manuscript.
Conflict-of-interest statement: The authors declare no conflicting interests related to this article.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist and this manuscript was prepared and revised according to these guidelines.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Rupert W Leong, AGAF, FRACP, MBBS, MD, Professor, Department of Gastroenterology and Hepatology, Macquarie University Hospital, 3 Technology Place, Sydney 2109, New South Wales, Australia. rupertleong@outlook.com
Received: October 18, 2019
Peer-review started: October 18, 2019
First decision: November 22, 2019
Revised: December 2, 2019
Accepted: December 13, 2019
Article in press: December 13, 2019
Published online: December 21, 2019
Abstract
BACKGROUND

The worldwide epidemiology of inflammatory bowel disease (IBD) is rapidly changing. Increasing Crohn’s disease (CD) and ulcerative colitis (UC) incidence and prevalence have been recorded in developing regions such as Asia, Africa and Eastern Europe where it was previously thought to be uncommon. Whether this is also the case in South America is not well known. Demonstration that developing regions worldwide have increasing IBD incidence would indicate that environmental change plays a significant role in the development of IBD.

AIM

To report the incidence, prevalence and disease characteristics of CD and UC within the South American continent.

METHODS

A systematic review was conducted by searching published studies in major international and regional databases (MEDLINE, EMBASE and Scopus) between January 1990 and December 2018. Outcomes considered were incidence, prevalence, phenotype, environmental and genetic factors, ethnicity and gender. A pair of independent reviewers screened and reviewed all identified articles.

RESULTS

One hundred and sixty two citations were initially retrieved with 18 studies included in this systematic review. The majority of included studies were from Brazil (n =13, 72%). The incidence of UC ranged from 4.3-5.3/100000 person-years whilst the incidence of CD ranged from 0.74-3.5/100000 person-years. Prevalence ranged from 15.0-24.1/100000 inhabitants for UC and from 2.4-14.1/100000 inhabitants for CD. The incidence and prevalence of both UC and CD has increased significantly in Brazil over the past 21 years. Pancolitis was the most common disease distribution in patients with UC whilst colonic involvement was the most common distribution in CD. People residing in urban areas were at higher risk of developing both CD and UC.

CONCLUSION

The IBD burden in South America is increasing at a rate possibly even greater than other developing regions around the world. There is a paucity of high-quality epidemiological studies and further robust and representative data are required to further explore modifiable risk factors and disease phenotypes.

Keywords: Inflammatory bowel disease, Crohn’s disease, Ulcerative colitis, South America, Epidemiology

Core tip: The worldwide epidemiology of inflammatory bowel disease (IBD) is rapidly changing with increasing disease incidence and prevalence noted in developing regions such as Asia, Africa and Eastern Europe where it was previously thought to be uncommon. Whether this is the case in South America was previously not well known. Our systematic review demonstrates that the IBD burden in South America is precipitously increasing, particularly in industrialised regions. With a total population exceeding 400 million, the South American continent is expected to carry a significant proportion of the future global IBD burden.