Molecular Epidemiology of Helicobacter pylori Infection in a Minor Ethnic Group of Vietnam: A Multiethnic, Population-Based Study

Abstract

The <i>Helicobacter pylori</i>-induced burden of gastric cancer varies based on geographical regions and ethnic grouping. Vietnam is a multiethnic country with the highest incidence of gastric cancer in Southeast Asia, but previous studies focused only on the Kinh ethnic group. A population-based cross-sectional study was conducted using 494 volunteers (18-78 years old), from 13 ethnic groups in Daklak and Lao Cai provinces, Vietnam. <i>H. pylori</i> status was determined by multiple tests (rapid urease test, culture, histology, and serology). <i>cagA</i> and <i>vacA</i> genotypes were determined by PCR-based sequencing. The overall <i>H. pylori</i> infection rate was 38.1%. Multivariate analysis showed that variations in geographical region, age, and ethnicity were independent factors associated with the risk of <i>H. pylori</i> acquisition. Therefore, multicenter, multiethnic, population based study is essential to assess the <i>H. pylori</i> prevalence and its burden in the general population. Only the E De ethnicity carried strains with Western-type CagA (82%) and exhibited significantly lower gastric mucosal inflammation compared to other ethnic groups. However, the histological scores of Western-type CagA and East-Asian-type CagA within the E De group showed no significant differences. Thus, in addition to bacterial virulence factors, host factors are likely to be important determinants for gastric mucosal inflammation and contribute to the Asian enigma.