The Increasing Trend of the Generational Helicobacter pylori-Naïve Prevalence Among Japanese Individuals Born Between 1925 and 2015: A Systematic Review and Meta-Regression Analysis.

[BACKGROUND] The World Health Organization has confirmed that Helicobacter pylori is a carcinogen associated with gastric cancer (GC). Although a recent increasing trend in the prevalence of the H. pylori-naïve status has been reported, the precise values of each generation have not yet been specified. This study aimed to confirm the generational H. pylori-naïve prevalence in Japan.

[MATERIALS AND METHODS] Scientific articles available in PubMed and EMBASE between January 2014 and June 2024 were systematically searched. Publications that specified the generational H. pylori-naïve prevalence were included in the analysis. Publications that did not describe the prevalence of H. pylori-naïve individuals and the definition of H. pylori-eradicated individuals were excluded. A meta-regression analysis with a logistic mixed effect model was conducted to predict the generational prevalence of the H. pylori-naïve status. In this model, birth year was incorporated as a spline function to model non-linear trends, and study differences were included as random effects.

[RESULTS] A total of 899 publications were identified. After screening, eight publications were included in the final analysis. Nine different study groups comprising 46,704 individuals included in those publications were identified and analyzed. The calculated H. pylori-naïve prevalence rates among the average cohort were 21.1% for births in 1930, 47.2% for births in 1950, 75.3% for births in 1970, 91.7% for births in 1990, and 97.7% for births in 2010.

[CONCLUSIONS] The H. pylori-naïve prevalence increased dramatically with more recent birth years and reached a plateau of over 95%, especially after 2000. The current GC screening strategy can be modified based on this finding.