Helicobacter pylori prevalences and risk factors among school beginners ina German urban center and its rural county

In 1998, the Helicobacter pylori [C-13]urea breath test was offered to all school beginners (birth cohort 1991/1992) in the city of Leipzig and in Lei pzig County, Germany, to determine the colonization prevalence and potentia l transmission pathways of the bacterium. A total of 3,347 school beginners participated in the test, and 2,888 parents completed the detailed, self-a dministered questionnaire. The H. pylori prevalence was 6.5% [95% confidenc e interval (CI), 5.3-7.6] in the city and 5.7% (CI, 4.2-7.0) in the county. Using cluster analysis (WARD's method, Euclidean distances), we identified different sets of variables (confirmed by multivariate logistic regression analyses [odds ratios (ORs)] that are significantly associated with H. pyl ori positivity. Among city children, the risk is significantly increased wi th contact to a pet hamster (OR = 2.4; 95% CI, 1.2-4.7; p < 0.015) and trav els to Asian countries (OR = 3.7; 95% CI, 1.6-8.7; p < 0.002). Among county children, N. pylori positivity increased significantly with drinking of wa ter from nonmunicipal sources (OR = 16.4; 95% CI, 3.1-88.5; p < 0.001), mor e than 3 children living in a household (OR = 4.2; 95% CI, 1.2-14.6; p < 0. 02), and contact with pet hamsters (OR = 2.4; 95% CI, 1.0-5.7; p < 0.04). T hese data suggest that, in a general population sample, indirect fecal-oral transmission and living conditions are important risk factors in the sprea d of H. pylori infection. However, clinical symptoms do not necessarily ind icate H. pylori positivity.