Prevalence of and risk factors for helicobacter pylori infection in school children in mexico

PURPOSE: This study examined the prevalence of Helicobacter pylori (H. pylori) infection in school children from an urban area in Northwest Mexico and attempted to identify the risk factors that predispose children to infection in the community. METHODS: The cross-sectional study was conducted in 1997/98 in the poorest socio-economic sectors of the city of Hermosillo, Sonora, among 178 children aged 9 and 10 years. H. pylori status was determined in children by the accurate and safe non-invasive 13C-urea breath test. Family socio-demographic/socio-economic status and living conditions data were elicited from parents by interview via structured questionnaires and/or direct observation. RESULTS: The overall prevalence rate of H. pylori infection for the children in Hermosillo as determined by this study was 47.1%. The overall prevalence rate of H. pylori infection was not found to be related to either gender (p = 0.531) nor to the two age groups (p = 0.483). It was not related to childʹs birthplace (p = 0.291) even after controlling for age and gender. However, the overall prevalence of infection was strongly and significantly associated with the parentʹs birthplace; rural-born mother (p = 0.028) and rural-born father (p = 0.029). There was a noticeable lack of statistical association with the presence of animals at home (p = 0.988) and with direct contact with indoor/outdoor animals for study children (p = 0.099). When all of the explanatory variables that were significant in the bivariate analysis were fitted into a direct logistic regression model, the same strong effect of fatherʹs birth place (rural setting), number of siblings (greater-or-equal, slanted3 per family), type of main water supply (one tap in the yard) and the sharing of bed by the study child were observed as potential risk factors for acquiring the infection. CONCLUSIONS: The findings indicate that high prevalence rate of H. pylori infection observed on study children seems to depend on factors related to poor living conditions, particularly (but not exclusively) number of children, ruralism (rural-born father), the sharing a bed in childhood and type of main water supply (one tap in the yard).