Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 14, 2019; 25(26): 3344-3358
Published online Jul 14, 2019. doi: 10.3748/wjg.v25.i26.3344
Gastro-duodenal disease in Africa: Literature review and clinical data from Accra, Ghana
Timothy N Archampong, Richard H Asmah, Cathy J Richards, Vicki J Martin, Christopher D Bayliss, Edília Botão, Leonor David, Sandra Beleza, Carla Carrilho
Timothy N Archampong, Department of Medicine and Therapeutics, School of Medicine and Dentistry, University of Ghana, Accra Box 4236, Ghana
Timothy N Archampong, Christopher D Bayliss, Sandra Beleza, Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, United Kingdom
Richard H Asmah, Department of Medical Laboratory Sciences, School of Biomedical and Allied Health Sciences, University of Ghana, Accra Box 4236, Ghana
Cathy J Richards, Vicki J Martin, Department of Histopathology, Leicester Royal Infirmary, Leicester LE1 5WW, United Kingdom
Edília Botão, Carla Carrilho, Department of Pathology, Maputo Central Hospital, Maputo POBox 1164, Mozambique
Leonor David, Department of Pathology, Medical Faculty of the University of Porto, Porto 4200-465, Portugal
Leonor David, Institute of Molecular Pathology and Immunology at the University of Porto (Ipatimup), Porto 4200-465, Portugal
Leonor David, Instituto de Investigação e Inovação em Saúde (i3S), University of Porto, Porto 4200-465, Portugal
Carla Carrilho, Department of Pathology, Faculty of Medicine, Eduardo Mondlane University, Maputo POBox 257, Mozambique
Author contributions: All authors equally contributed to this paper with conception and design of the study, literature review and analysis, drafting and critical revision and editing, and approval of the final version.
Supported by University of Ghana Research fund URF/5/ILG-003/2011-2012 to Timothy N Archampong and by the Medical Research Council UK with grant MR/M01987X/1 to Sandra Beleza.
Conflict-of-interest statement: No potential conflicts of interest.
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:
Corresponding author: Timothy N Archampong, FRCP, MBChB, Doctor, Consultant Gastroenterologist, Department of Medicine and Therapeutics, School of Medicine and Dentistry, University of Ghana, Korle-bu, Accra Box 4236, Ghana.
Telephone: +233-302-968-376
Received: March 15, 2019
Peer-review started: March 15, 2019
First decision: April 30, 2019
Revised: May 14, 2019
Accepted: May 31, 2019
Article in press: June 1, 2019
Published online: July 14, 2019

Gastroduodenal disease (GDD) was initially thought to be uncommon in Africa. Amongst others, lack of access to optimal health infrastructure and suspicion of conventional medicine resulted in the reported prevalence of GDD being significantly lower than that in other areas of the world. Following the increasing availability of flexible upper gastro-intestinal endoscopy, it has now become apparent that GDD, especially peptic ulcer disease (PUD), is prevalent across the continent of Africa. Recognised risk factors for gastric cancer (GCA) include Helicobater pylori (H. pylori), diet, Epstein-Barr virus infection and industrial chemical exposure, while those for PUD are H. pylori, non-steroidal anti-inflammatory drug (NSAID)-use, smoking and alcohol consumption. Of these, H. pylori is generally accepted to be causally related to the development of atrophic gastritis (AG), intestinal metaplasia (IM), PUD and distal GCA. Here, we perform a systematic review of the patterns of GDD across Africa obtained with endoscopy, and complement the analysis with new data obtained on pre-malignant gastric his-topathological lesions in Accra, Ghana which was compared with previous data from Maputo, Mozambique. As there is a general lack of structured cohort studies in Africa, we also considered endoscopy-based hospital or tertiary centre studies of symptomatic individuals. In Africa, there is considerable heterogeneity in the prevalence of PUD with no clear geographical patterns. Furthermore, there are differences in PUD within-country despite universally endemic H. pylori infection. PUD is not uncommon in Africa. Most of the African tertiary-centre studies had higher prevalence of PUD when compared with similar studies in western countries. An additional intriguing observation is a recent, ongoing decline in PUD in some African countries where H. pylori infection is still high. One possible reason for the high, sustained prevalence of PUD may be the significant use of NSAIDs in local or over-the-counter preparations. The prevalence of AG and IM, were similar or modestly higher over rates in western countries but lower than those seen in Asia. . In our new data, sampling of 136 patients in Accra detected evidence of pre-malignant lesions (AG and/or IM) in 20 individuals (14.7%). Likewise, the prevalence of pre-malignant lesions, in a sample of 109 patients from Maputo, were 8.3% AG and 8.3% IM. While H. pylori is endemic in Africa, the observed prevalence for GCA is rather low. However, cancer data is drawn from country cancer registries that are not comprehensive due to considerable variation in the availability of efficient local cancer reporting systems, diagnostic health facilities and expertise. Validation of cases and their source as well as specificity of outcome definitions are not explicit in most studies further contributing to uncertainty about the precise incidence rates of GCA on the continent. We conclude that evidence is still lacking to support (or not) the African enigma theory due to inconsistencies in the data that indicate a particularly low incidence of GDD in African countries.

Keywords: Gastroduodenal, Peptic ulcer, Gastric cancer, Africa, Pre-malignant, Atrophy, Intestinal metaplasia, Duodenal ulcer, Gastric ulcer

Core tip: Peptic ulcer disease (PUD) is not uncommon in Africa. There is considerable heterogeneity in its prevalence with no clear geographical patterns. There are further differences in PUD within-country despite endemic Helicobater pylori infection. Most African tertiary-centre studies have higher prevalence of PUD when compared with western countries. One possible reason for its sustained prevalence is the significant use of non-steroidal anti-inflammatory drugs in local preparations. The prevalence of atrophic gastritis and intestinal metaplasia were similar or modestly higher over western countries but lower than those seen in Asia. Contrastingly, a comparatively low prevalence for gastric cancer is usually observed in African centres, although these rates might be underestimated.