Review Article Helicobacter Pylori Infection, Virulence Genes’ Distribution and Accompanying Clinical Outcomes: the West Africa Situation

Review Article Helicobacter Pylori Infection, Virulence Genes’ Distribution and Accompanying Clinical Outcomes: the West Africa Situation

Hindawi BioMed Research International Volume 2019, Article ID 7312908, 13 pages https://doi.org/10.1155/2019/7312908 Review Article Helicobacter pylori Infection, Virulence Genes’ Distribution and Accompanying Clinical Outcomes: The West Africa Situation Eric Gyamerah Ofori ,1,2 Cynthia Ayefoumi Adinortey ,1 Ansumana Sandy Bockarie,3 Foster Kyei ,1 Emmanuel Ayitey Tagoe,4,5 and Michael Buenor Adinortey 2 1Department of Molecular Biology and Biotechnology, School of Biological Sciences, University of Cape Coast, Cape Coast, Ghana 2Department of Biochemistry, School of Biological Sciences, University of Cape Coast, Cape Coast, Ghana 3Department of Internal Medicine, School of Medical Sciences, University of Cape Coast, Cape Coast, Ghana 4West Africa Centre for Cell Biology of Infectious Disease and Pathogens, Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Legon, Ghana 5Department of Medical Laboratory Sciences, School of Biomedical and Allied Health Sciences, University of Ghana, Ghana Correspondence should be addressed to Michael Buenor Adinortey; [email protected] Received 15 May 2019; Revised 18 July 2019; Accepted 20 August 2019; Published 10 December 2019 Academic Editor: Gail B. Mahady Copyright © 2019 Eric Gyamerah Ofori et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Data on Helicobacter pylori (H. pylori) infection and virulence factors in countries across West Africa are scattered. is systematic review seeks to present an update on the status of H. pylori infection focusing on prevalence rate, distribution of virulent genes, and their link to clinical outcomes across countries in the western part of Africa. is information is expected to broaden the knowledge base of clinicians and researchers regarding H. pylori infection and associated virulence factors in West African countries. Search Method. A comprehensive search of the scientic literature in PubMed and ScienceDirect was conducted using the search terms including “Helicobacter pylori infection in West Africa”. Databases were sourced from January 1988 to December 2018. Results. Data on the incidence of H. pylori infection and related pathological factors were found for some countries, whereas others had no information on it. Smoking, alcohol, exposure to high levels of carcinogens and diet were reported to be involved in the pathogenesis of gastroduodenal diseases and gastric cancer. Besides the environmental factors and genetic characteristics, there are important characteristics of H. pylori such as the ability to infect, replicate, and persist in a host that have been associated with the pathogenesis of various gastroduodenal diseases. Concluding Remarks. is systematic search has provided information so far available on H. pylori virulence factors and clinical outcomes in West Africa. Accordingly, this piece has identied gaps in the body of knowledge highlighting the need for more studies to clarify the role of H. pylori virulence factors and associated clinical outcomes in the burden of this bacterial infection in West Africa, as data from these countries do not give the needed direct relation. 1. Introduction from H. pylori has also been linked to some other diseases such as iron-deciency anemia [5, 6], immune thrombocyto- Helicobacter pylori (H. pylori) are common microaerophilic penia (ITP), [5, 7] cardiovascular diseases, [8, 9], hepatobiliary bacteria known to obstinately inhabit the human stomach diseases [10, 11], diabetes mellitus [12], allergies, and asthma mucous layer, aecting about half the world’s population [1–3]. [13] among others. Although Marshall and Warren [14] e pathogen is known to be present in the mucous, on the reported the rst isolation of H. pylori in 1983, isolation of the surface of the stomach lining and its presence causes chronic organism is still not commonly done in West Africa with only inammation, which remains a major cause of prolonged gas- few countries such as Senegal [15] and Ghana [16] having tritis. Also, H. pylori has been identied to increase the risk of recorded their rst successful isolation from gastric biopsy. developing gastric adenocarcinoma [4]. Apart from the gas- ere is no certainty in the mode of transmission for trointestinal tract (GIT) related diseases such as gastroesoph- H. pylori infection; however, various epidemiological studies ageal reux disease, gastric ulcer and duodenal ulcer, infection have made several claims in this regard. e primary means 2 BioMed Research International of spread of the disease has been linked to transmission from Several factors have been reported to contribute to this vari- one individual to another and usually higher when occurring ation such as, host genetic factors, type of H. pylori virulence within a family [17–19]. e spread from person-to-person factors and sensitivity of the method of detection employed has been identified to be the most likely and could be by [38, 39]. ere is inadequate information on the role of these oral-oral, gastro-oral or fecal-oral [20]. In this regard, the factors in H. pylori infection rates and associated clinical out- practice of good hygiene and improved living conditions comes across the countries in the Western area of Africa which becomes an essential factor in reducing the rate of transmis- makes tackling of the growing disease burden increasingly sion of the infection [21]. Infection occurs in children as well difficult. Assembling data on the type of virulent genes, factors and an infected child maintains a strain, which has a genetic involved in infection and associated clinical outcome is, there- characteristic indistinguishable from that observed in their fore, important [40, 41]. is systematic review hence looks parents [22–24]. ese characteristics remain unchanged at available information in the West African zone on the prev- upon any alteration in the environment in which they are alence of H. pylori infection, virulence factors and their rela- found. tion to clinical outcomes. e prevalence of infection from H. pylori varies geo- graphically with the developing world carrying the higher burden [25]. Infection in peptic ulcer diseases (PUDs) 2. Method of Literature Search patients ranges from almost 25% in countries of the indus- trialized world, and is anticipated to be around 90% in under- A comprehensive search of the scientific literature in PubMed developed countries [26, 27]. e prevalence across countries and ScienceDirect was conducted using the search terms in the West African region is generally high with variations “Helicobacter pylori infection in West Africa”. e search was existing from country to country. e reportedly high prev- repeated with “West Africa” replaced with each of the follow- alence observed in Africa (79.1%) and Asia (54.7%) as com- ing countries; Sierra Leone, Cape Verde, Ghana, Liberia, pared to lower prevalence found in other geographic Benin, Senegal, Sao tome and Principle, Mali, Burkina Faso, locations such as Northern America (37.1%) and Oceania Mauritania, Cote D’ivoire, Guinea Bissau, Niger, Guinea, e (24.4%) [28] have been found not to correlate with the rather Gambia, and Togo. e key words “Helicobacter pylori” was low occurrence of gastric cancer [29, 30]. is situation has replaced with “H. pylori” and the search was repeated. Some been described as the “Asian and African enigmas”. ese other keywords employed were “Helicobacter pylori”, “epide- so-called “enigmas” have been explained by several factors miology”, “prevalence”, and “virulent factors”. e search including host genetic and immune response, different protocol is shown in Figure 1. tumor-inducing potential of explicit strains of H. pylori as e search in PubMed was done with the following acti- well as environmental factors [29, 31]. Again, insufficient vated filters; publication date from 1st January 1988 to 31st African population sampling obtained through endoscopy December 2018, language filter had English and French acti- as well as poor access to health care has also been found to vated and the species selected was Human. Filters activated contribute to this so-called mystery. In this regard, a stronger for the search in ScienceDirect database were the selection of and elaborate data on gastric ulcer in Africans and the prev- the article types; Review articles, Research articles, and alence of associated cancer have established that the low mini-reviews as well as the year range of 1988–2018. Duplicate occurrence is not exactly so [32]. In contrast to the “Asian searches were first removed; aer which the abstracts of arti- enigma”, a report by Irino et al. [33] shows that the incidence cles retrieved were reviewed for relevance before an attempt of gastric cancer (GC) is mainly high in Asian countries, a was made to retrieve the full paper. Selection of articles was situation attributed to the high prevalence in infection from based on the following considerations; (1) Study participants H. pylori. were West Africans. (2) Participants who showed up for endos- It is imperative to mention that an individual that is copy at a gastroenterology unit and diagnosed with H. pylori infected with H. pylori faces a strenuous task of getting rid of infection. (3) Studies investigating virulent factors; Vacuolating the bacterium and hence disease eradication, a situation that cytotoxin (VacA), Cytotoxin-associated gene A (cagA), Outer

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