RESUMO
BACKGROUND: Synthesised data on the prevalence of, and factors associated with, paediatric Helicobacter pylori infection at the global level remain scarce. We aimed to estimate the global prevalence of H pylori infection and its associated factors in children and adolescents. METHODS: In this systematic review and meta-analysis, we searched PubMed, Embase, MEDLINE, and Scopus for observational population-based studies published between database inception and Oct 25, 2021, without language or geographical restrictions. We included studies that reported the prevalence of H pylori infection in children aged 18 years or younger. Records were screened and data were extracted using a standardised extraction form. We estimated the worldwide prevalence of H pylori infection in children (our main outcome) using multilevel mixed-effects meta-regression and then stratified prevalence by diagnostic method (serology vs urea breath tests or stool antigen tests). We analysed the significance of associated factors using a random-effects meta-analysis. This study is registered in PROSPERO, CRD42020209717. FINDINGS: We identified 3181 records, of which 198 articles with 632 data points from 152 650 children were included. The overall global prevalence of H pylori infection in children was 32·3% (95% CI 27·3-37·8), which varied by diagnostic test (28·6% [23·0-35·0] for serology vs 35·9% [29·2-43·2] for urea breath tests or stool antigen tests). Regardless of diagnostic test, the prevalence of H pylori infection was significantly higher in low-income and middle-income countries than in high-income countries (43·2% [36·5-50·2] vs 21·7% [16·9-27·4]; p<0·0001) and in older children than in younger children (41·6% [35·6-47·8] in 13-18-year-olds vs 33·9% [28·6-39·7] in 7-12-year-olds vs 26·0% [21·4-31·0] in 0-6-year-olds; p<0·0001). Paediatric H pylori infection was significantly associated with lower economic status (odds ratio [OR] 1·63 [95% CI 1·46-1·82]), more siblings or children (1·84 [1·44-2·36]), room sharing (1·89 [1·49-2·40]), no access to a sewage system (1·60 [1·22-2·10]), having a mother infected with H pylori (3·31 [2·21-4·98]), having a sibling or siblings infected with H pylori (3·33 [1·53-7·26]), drinking unboiled or non-treated water (1·52 [1·32-1·76]), and older age (OR per year 1·27 [1·15-1·40]). INTERPRETATION: H pylori infection is still highly prevalent in children and adolescents globally. Our findings can help to guide further research and the development and implementation of preventive and therapeutic measures to reduce H pylori infection in children. FUNDING: None.