Intergenerational reduction in Helicobacter pylori prevalence is similar between different ethnic groups living in a Western city

Objective: Helicobacter pylori colonisation rates in childhood have declined in Western populations, but it is unknown whether this trend is similar in children of non-Western ethnic backgrounds, born in a Western country. We aimed to identify H. pylori status in children, and determine mother-to-child transmission and risk factors for colonisation. Design: Antibodies against H. pylori and cytotoxinassociated gene A (CagA) were measured in children participating in a population-based prospective cohort study in Rotterdam, the Netherlands. Information on demographics and characteristics was collected using questionnaires. Results: We analysed the serum of 4467 children (mean age 6.2 years±0.4 SD) and compared the results with the H. pylori status of their mothers (available for 3185 children). Overall, 438 (10%) children were H. pyloripositive, of whom 142 (32%) were CagA-positive. Independent risk factors for colonisation were: maternal H. pylori positivity (OR 2.12; 95% CI 1.62 to 2.77), non-Dutch ethnicity (OR 2.05; 95% CI 1.54 to 2.73), female gender (OR 1.47; 95% CI 1.20 to 1.80) and lower maternal education level (OR 1.38; 95% CI 1.06 to 1.79). Comparing mothers and children, we found an intergenerational decrease of 76% and 77% for Hp⁺ CagA^- and Hp⁺ CagA⁺-strains, respectively, consistent across all nine ethnic groups studied. Male gender, higher maternal educational level and no older siblings, were independently associated with absence of H. pylori. Conclusions: Although the highest H. pylori and CagA prevalence was found in children of non-Dutch ethnicities, the decreased colonisation rates were uniform across all ethnic groups, implying the importance of environmental factors in H. pylori transmission in modern cities, independent of ethnicity.