RESUMO
OBJETIVE: H. pylori infection is acquired early in life, but symptoms occur mainly in adults. The mode of transmission remains unclear, but several studies have demonstrated that the microorganism may be transmitted orally. H. pylori has been detected in the oral cavity of children, and some authors have studied infection prevalence due to the importance of the bacteria in gastric and extragastric pathology. In México, little is known about H. pylori prevalence in the oral cavity of asymptomatic children, so the aims of this study were to estimate the prevalence of H. pylori in asymptomatic children and evaluate factors associated with the infection. DESING: We studied 162 asymptomatic children of 3.025±1.474 years of age from a kindergarten in México City. Oral swabs, rotating around to cheeks inside of oral cavity were obtained to determine H. pylori, using the polymerase chain reaction for 16S rRNA and glmM genes. RESULTS: We detected a 13% prevalence of H. pylori infection by PCR, and the results were confirmed by sequencing and showed a >97% identity with H. pylori. We observed increased infection with age. No association between H. pylori infection and variables such as sex, family history of gastric diseases, crowding or pets in the home were found. CONCLUSION: H. pylori infection in the oral cavity is frequent among asymptomatic children in México, which represents a risk of infection for other family members and for other children in educational facilities. Early diagnosis is essential for control of the infection and for the development of preventive strategies in childhood.