Background: Differences in prevalence of H. pylori among racial and ethnic groups have been described worldwide. The aim of the present study was to evaluate the seroprevalence of H. pylori infection and factors associated with the H. pylori infection among Tay children and adults living in Vietnam.

Materials and methods: In a cross-sectional study 1,094 healthy individuals of all generations living together in the same home were selected from 278 households, based on cluster sampling of residential location between September and December 2013 in Langson province. H. pylori infection status was determined by serology test on samples obtained at each visit. A questionnaire was filled out at the start of the study. H. pylori serology data were analyzed using χ2 test and logistic regression models.

Results: An overall H. pylori seroprevalence was 46.8%. H. pylori seroprevalence was 51.4% in adults versus 41.4% in children ≤18 years old (p<0.05). Regular hand washing after defecation and breastfeeding over 12 months were protective factors for H. pylori infection [OR (95%CI): 0.73, (0.39-0.92); 0.71 (0.35-0.94); respectively]. H. pylori infected mothers, first siblings and grandparents were found as risk factors for H. pylori infection in children [OR (95%CI): 2.98 (1.13-3.14), 1.4 (1.0-3.12), 1.41 (1.11-4.64); respectively]. No other factors such as size of household or sibling, infected fathers, regular sharing bed, collective life initiation and antibiotic use were found to be significant risk factors for infection

Conclusion: The first community-based study in Tay population showed moderate and indifferent rates of H. pylori infection. Data from the present study are consistent with intra-familial H. pylori transmission and suggest that improvement of living conditions should be protective against infection.