{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,14]],"date-time":"2026-05-14T18:18:32Z","timestamp":1778782712170,"version":"3.51.4"},"reference-count":19,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2023,2,17]],"date-time":"2023-02-17T00:00:00Z","timestamp":1676592000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Med."],"abstract":"<jats:sec><jats:title>Background<\/jats:title><jats:p>Notable geographic and temporal variations in the prevalence and genotypes of <jats:italic>Helicobacter pylori<\/jats:italic>, in relation to gastric pathologies, have been observed; however, their significance and trends in African populations is scarcely described. The aim of this study, was to investigate the association of <jats:italic>H. pylori<\/jats:italic> and its respective <jats:italic>CagA<\/jats:italic> and vacuolating cytotoxin A (<jats:italic>VacA<\/jats:italic>) genotypes with gastric adenocarcinoma, and to describe the trends of <jats:italic>H. pylori<\/jats:italic> genotypes over an 8-year period (2012\u20132019).<\/jats:p><\/jats:sec><jats:sec><jats:title>Materials and methods<\/jats:title><jats:p>A total of 286 samples of gastric cancer cases and benign controls (one-to-one matching), from three main cities in Kenya, between 2012 and 2019 were included. Histologic evaluation, and <jats:italic>CagA<\/jats:italic> and <jats:italic>VacA<\/jats:italic> genotyping using PCR, was performed. Distribution of <jats:italic>H. pylori<\/jats:italic> genotypes was presented in proportions. To determine association, a univariate analysis was conducted using a Wilcoxon rank sum test for continuous variables, and a Chi-squared test or Fisher\u2019s exact test for categorical data.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The <jats:italic>VacA s1m1<\/jats:italic> genotype was associated with gastric adenocarcinoma, {odds ratio (OR) = 2.68 [confidence interval (CI) of 95%: 0.83\u20138.65]; <jats:italic>p<\/jats:italic> = 0.108}, whilst <jats:italic>VacA s2m2<\/jats:italic> was associated with a reduced probability of gastric adenocarcinoma [OR = 0.23 (CI 95%: 0.07\u20130.78); <jats:italic>p<\/jats:italic> = 0.031]. No association between cytotoxin associated gene A (<jats:italic>CagA<\/jats:italic>) and gastric adenocarcinoma was observed.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>Over the study period, an increase in all genotypes of <jats:italic>H. pylori<\/jats:italic> was seen, and although no predominant genotype was noted, there was significant year-to-year variation, with <jats:italic>VacA s1<\/jats:italic> and <jats:italic>VacA s2<\/jats:italic> showing the greatest variation. <jats:italic>VacA s1m1<\/jats:italic> and <jats:italic>VacA s2m2<\/jats:italic> were associated with increased, and reduced risk of gastric cancer, respectively. Intestinal metaplasia and atrophic gastritis did not appear to be significant in this population.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fmed.2023.1119513","type":"journal-article","created":{"date-parts":[[2023,2,17]],"date-time":"2023-02-17T06:01:53Z","timestamp":1676613713000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":4,"title":["Pattern and trends of Helicobacter pylori genotypes in gastric cancer: A Kenyan 8-year study"],"prefix":"10.3389","volume":"10","author":[{"given":"Priscilla","family":"Njenga","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Allan","family":"Njau","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zahir","family":"Moloo","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gunturu","family":"Revathi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Evariste","family":"Tshibangu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yoshio","family":"Yamaoka","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2023,2,17]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0197695","article-title":"Prevalence of Helicobacter pylori and its CagA subtypes in gastric cancer and duodenal ulcer at an Austrian tertiary referral center over 25 years.","volume":"13","author":"Kamogawa-Schifter","year":"2018","journal-title":"PLoS One."},{"key":"B2","doi-asserted-by":"publisher","first-page":"420","DOI":"10.1053\/j.gastro.2017.04.022","article-title":"Global prevalence of Helicobacter pylori infection: systematic review and meta-analysis.","volume":"153","author":"Hooi","year":"2017","journal-title":"Gastroenterology."},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.3390\/toxins11110677","article-title":"Helicobacter pylori virulence factors exploiting gastric colonization and its pathogenicity.","volume":"11","author":"Ansari","year":"2019","journal-title":"Toxins (Basel)."},{"key":"B4","doi-asserted-by":"publisher","first-page":"233","DOI":"10.4236\/ojmm.2020.104020","article-title":"Prevalence and endoscopic findings of Helicobacter pylori infection among dyspeptic patients in Kenya.","volume":"10","author":"Mwangi","year":"2020","journal-title":"Open J Med Microbiol."},{"key":"B5","doi-asserted-by":"publisher","first-page":"209","DOI":"10.3322\/caac.21660","article-title":"Global cancer statistics 2020: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries.","volume":"71","author":"Sung","year":"2021","journal-title":"CA Cancer J Clin."},{"key":"B6","doi-asserted-by":"publisher","first-page":"3875","DOI":"10.3748\/wjg.v20.i14.3875","article-title":"Gastric cancer in africa: current management and outcomes.","volume":"20","author":"Asombang","year":"2014","journal-title":"World J Gastroenterol."},{"key":"B7","first-page":"177","article-title":"Schistosomes, liver flukes and Helicobacter pylori.","volume":"61","year":"1994","journal-title":"IARC Monogr Eval Carcinog Risks Hum."},{"key":"B8","doi-asserted-by":"publisher","first-page":"109","DOI":"10.1016\/j.meegid.2018.02.022","article-title":"Genetic populations and virulence factors of Helicobacter pylori.","volume":"60","author":"Kabamba","year":"2018","journal-title":"Infect Genet Evol."},{"key":"B9","doi-asserted-by":"publisher","first-page":"214","DOI":"10.1016\/j.micpath.2018.03.004","article-title":"Risk of gastric cancer in association with Helicobacter pylori different virulence factors: a systematic review and meta-analysis.","volume":"118","author":"Pormohammad","year":"2018","journal-title":"Microb Pathog."},{"key":"B10","first-page":"436","article-title":"Association of Helicobacter pylori VacA gene polymorphisms and CagA gene with clinical outcome in dyspeptic patients.","volume":"5","author":"M\u2019itonga","year":"2015","journal-title":"Int J Health Sci Res."},{"key":"B11","doi-asserted-by":"publisher","first-page":"2053","DOI":"10.1002\/ijc.29674","article-title":"Incidence of cancer in Nairobi, Kenya (2004-2008).","volume":"137","author":"Korir","year":"2015","journal-title":"Int J Cancer."},{"key":"B12","doi-asserted-by":"publisher","first-page":"3906","DOI":"10.1128\/JCM.43.8.3906-3916.2005","article-title":"Distinct diversity of vacA, cagA, and cagE genes of Helicobacter pylori associated with peptic ulcer in Japan.","volume":"43","author":"Yamazaki","year":"2005","journal-title":"J Clin Microbiol."},{"key":"B13","doi-asserted-by":"publisher","first-page":"876","DOI":"10.1128\/JCM.05562-11","article-title":"Association between Helicobacter pylori virulence factors and gastroduodenal diseases in Okinawa, Japan.","volume":"50","author":"Matsunari","year":"2012","journal-title":"J Clin Microbiol."},{"key":"B14","doi-asserted-by":"publisher","DOI":"10.3390\/toxins12090556","article-title":"Whole genome sequencing reveals virulence potentials of Helicobacter pylori strain KE21 isolated from a kenyan patient with gastric signet ring cell carcinoma.","volume":"12","author":"Mwangi","year":"2020","journal-title":"Toxins (Basel)."},{"key":"B15","first-page":"51","article-title":"Gastric cancer in Kenya.","volume":"31","author":"Lodenyo","year":"2018","journal-title":"Afr J Health Sci."},{"key":"B16","doi-asserted-by":"publisher","first-page":"306","DOI":"10.1016\/j.chom.2014.02.008","article-title":"Helicobacter pylori CagA and gastric cancer: a paradigm for hit-and-run carcinogenesis.","volume":"15","author":"Hatakeyama","year":"2014","journal-title":"Cell Host Microbe."},{"key":"B17","doi-asserted-by":"publisher","first-page":"8","DOI":"10.1111\/hel.12251","article-title":"Pathogenesis of Helicobacter pylori infection.","volume":"1","author":"Sgouras","year":"2015","journal-title":"Helicobacter."},{"key":"B18","doi-asserted-by":"publisher","first-page":"23","DOI":"10.3390\/toxins9100316","article-title":"Helicobacter pylori vacuolating toxin and gastric cancer.","volume":"9","author":"McClain","year":"2017","journal-title":"Toxins (Basel)."},{"key":"B19","doi-asserted-by":"publisher","first-page":"1203","DOI":"10.1111\/j.1742-4658.2011.08036.x","article-title":"Assembly and molecular mode of action of the Helicobacter pylori Cag type IV secretion apparatus.","volume":"278","author":"Fischer","year":"2011","journal-title":"FEBS J."}],"container-title":["Frontiers in Medicine"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fmed.2023.1119513\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,2,17]],"date-time":"2023-02-17T06:01:58Z","timestamp":1676613718000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fmed.2023.1119513\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,2,17]]},"references-count":19,"alternative-id":["10.3389\/fmed.2023.1119513"],"URL":"https:\/\/doi.org\/10.3389\/fmed.2023.1119513","relation":{},"ISSN":["2296-858X"],"issn-type":[{"value":"2296-858X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,2,17]]},"article-number":"1119513"}}