title: Epidemiology of Helicobacter pylori infection.
abstract: This review of recent publications related to the epidemiology of Helicobacter pylori highlights the origin of the infection, its changing prevalence, transmission, and outcome. A number of studies have addressed the ancestor roots of the bacteria, and the first genomewide analysis of bacterial strains suggests that its coexistence with humans is more ancient than previously thought. As opposed to the generally declining prevalence of H. pylori (including China and Japan), in Sweden, the prevalence of atrophic gastritis in the young population has risen. The prevalence of the infection remains high in the indigenous populations of the Arctic regions, and reinfection rates are high. A high prevalence is permanently found in the Siberian regions of Russia as well. Several studies, some of which used multiplex serology, addressed prevalence of and risks associated with various H. pylori serotypes, thereby enabling more precise risk assessment. Transmission of H. pylori was discussed, specifically fecal-oral transmission and the use of well-water and other unpurified water. Finally, the long-term course of H. pylori infection was considered, with an estimated 89% of noncardia gastric cancer cases being attributable to the infection.
authors.affiliation: Faculty of Medicine, University of Latvia, Riga, Latvia.|Riga East University Hospital, Riga, Latvia.|Digestive Diseases Centre GASTRO, Riga, Latvia.
authors.forename: Mārcis
authors.initials: M
authors.lastname: Leja
authors.affiliation: University of Leeds, Leeds, UK.
authors.forename: Anthony
authors.initials: A
authors.lastname: Axon
authors.affiliation: Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany.|Division of Preventive Oncology, German Cancer Research Center (DKFZ) and National Center for Tumor Diseases (NCT), Heidelberg, Germany.|German Cancer Consortium, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Hermann
authors.initials: H
authors.lastname: Brenner
mesh_terms: D018562:Disease Transmission, Infectious; D014943:Global Health; D016481:Helicobacter Infections / Q000150:complications / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D016480:Helicobacter pylori / Q000145:classification; D006801:Humans; D015995:Prevalence; D012307:Risk Factors; D065288:Serogroup; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000209:etiology
keywords: Helicobacter pylori; ancestor roots; epidemiology; outcomes; transmission; virulence factors