Birth cohort and age-specific trends in global Helicobacter pylori seroprevalence: A scoping review
The Lancet Regional Health - Americas
Birth Cohort and Age-Specific Trends in Global H. pylori Seroprevalence
Pieter Bruegel the Elder — Children’s Games (1560) Kunsthistorisches Museum · Vienna Over two hundred children fill a town square with more than eighty distinct games — each cohort carrying forward the same play, generation after generation. A portrait of childhood as a shared and recurring condition across time.
The Problem
Gastric cancer remains one of the leading causes of cancer death worldwide, even as incidence slowly falls. Its primary driver – Helicobacter pylori, a WHO class I carcinogen – has been declining for decades, but the pace and timing of that decline vary enormously by region, age, and generation. Until now, birth-cohort and age-specific trends in infection had barely been mapped at a global scale, leaving a blind spot in how we forecast future cancer burden and target prevention.
The Approach
We assembled the most comprehensive picture of global H. pylori seroprevalence to date: a scoping review of 229 publications – 250 datasets including NHANES – spanning 88 countries across every UN region, with samples collected between 1947 and 2023. Searching PubMed and Embase through June 2024, we extracted seroprevalence in asymptomatic, non-migrant populations and organized more than 375,000 data points by the UN geoscheme. Rather than reading single snapshots, we tracked how infection shifted across age groups and birth cohorts – exposing generational change that point-in-time studies miss.
What We Found
Seroprevalence varied more than three-fold across regions: highest in Africa (62·1%) and Latin America & the Caribbean (57·9%), lowest in Oceania (16·4%), with North America at 41·1%, Asia at 37·7%, and Europe at 36·2%. But coverage was deeply uneven – Europe (82 studies) and Asia (72) dominated the evidence base, while Africa contributed under 2% of all data despite holding 12·5% of the world’s population.
The generational signal was consistent everywhere: H. pylori seroprevalence fell in successive birth cohorts while still rising with age within each cohort. In Japan, predicted prevalence dropped from 60·9% among people born in 1910 to 6·6% among those born in 2000; South America and North America showed the same cohort-over-cohort decline. The pattern points to improving childhood living conditions as the engine of decline – but the rate differs sharply by region.
Age- and birth-cohort trends in H. pylori seroprevalence across UN regions, showing declining prevalence in younger generations.
The Americas Gap
The Americas – and Central America and the Caribbean above all – had markedly less data than other regions, too sparse to robustly resolve trends by both age and cohort. That blind spot matters: no country in the Americas runs a national H. pylori eradication program for asymptomatic populations, even as the absolute burden of gastric cancer is projected to rise there with aging populations and persistently high infection. The places with the weakest surveillance are among those with the most to gain from it.
Why It Matters
Younger generations are increasingly free of H. pylori – a hopeful signal that gastric cancer incidence may keep falling. Yet more than a third of people worldwide remain infected, sustaining substantial cancer risk, and the Americas’ data gaps leave millions unaccounted for. Folding these birth-cohort and age patterns into epidemiological models would sharpen gastric-cancer projections and pinpoint the populations where targeted prevention would do the most good.
Citation
Taylor, C.S., McMahon, M.V., Ward, Z.J., Alarid-Escudero, F., Camargo, M.C., Laszkowska, M., Roa, J., & Yeh, J.M. (2024). Birth cohort and age-specific trends in global Helicobacter pylori seroprevalence: A scoping review. The Lancet Regional Health - Americas, 100877. DOI: 10.1016/j.lana.2024.100877
Citation
@article{c.s.2025,
author = {C.S. , Taylor and M.V. , McMahon and Z.J. , Ward and F. ,
Alarid-Escudero and M.C. , Camargo and M. , Laszkowska and J. , Roa
and J.M. , Yeh},
title = {Birth Cohort and Age-Specific Trends in Global {Helicobacter}
Pylori Seroprevalence: {A} Scoping Review},
journal = {The Lancet Regional Health - Americas},
date = {2025-01-01},
url = {https://jorgeroac.com/publications/papers/peer-reviewed/hpylori-seroprevalence-scoping/},
doi = {10.1016/j.lana.2024.100877},
langid = {en}
}