Prevalence and determinants of Helicobacter pylori infection in preschool children: a population-based study from Germany.

BACKGROUND Helicobacter pylori is among the most common infections in humans and has been recognized as major cause of various gastroduodenal diseases. There is limited knowledge, however, on the prevalence and determinants of this infection in children. We addressed these issues in a population-based cross-sectional study in Southern Germany. METHODS Study subjects were all preschool children in Ulm, a city in the South of Germany, who were screened for school fitness by physicians of the public health service in 1996. Infection status was determined by 13C-urea breath test. In addition, the parents of the children were asked to fill out a standardized questionnaire. RESULTS In total, 945 out of the 1201 eligible preschool children participated in the study (response rate = 79%). The children were aged 5-8 years. The majority were of German nationality (72.6%). Overall, 127 children (13.4%) were infected with H. pylori. Nationality, place of residence in the first year of life and duration of living in Germany were strongly associated with H. pylori infection status. The prevalence varied from 4.8% (95% confidence interval [CI]: 3.3-6.8%) in children with German nationality who were born in Germany or had lived in Germany since their first year of life to 66.7% (95% CI: 29.9-92.5%) in the children with Turkish nationality who came to Germany after the first year of life. CONCLUSION Our results showed a large variation in prevalence of H. pylori infection in children living in the same geographical area according to nationality. They indicate an association between living conditions in early childhood and H. pylori infection and indicate that H. pylori associated morbidity may evolve very differently in population subgroups living in the same area.