The Prevalence ofHelicobacter pyloriVirulence Factors in Bhutan, Vietnam, and Myanmar Is Related to Gastric Cancer Incidence

Abstract

Gastric cancer is a significant health problem in Asia. Although the prevalence ofHelicobacter pyloriinfection is similar in Bhutan, Vietnam, and Myanmar, the incidence of gastric cancer is highest in Bhutan, followed by Vietnam and Myanmar. We hypothesized thatH. pylorivirulence factors contribute to the differences. The status ofcagA,vacA,jhp0562, andβ-(1,3)galT(jhp0563)was examined in 371H. pylori-infected patients from Bhutan, Vietnam, and Myanmar. Each virulence factor could not explain the difference of the incidence of gastric cancer. However, the prevalence of quadruple-positive forcagA,vacAs1,vacAm1, andjhp0562-positive/β-(1,3)galT-negative was significantly higher in Bhutan than in Vietnam and Myanmar and correlated with gastric cancer incidence. Moreover, gastritis-staging scores measured by histology of gastric mucosa were significantly higher in quadruple-positive strains. We suggest that thecagA,vacAs1,vacAm1, andjhp0562-positive/β-(1,3)galT-negative genotype may play a role in the development of gastric cancer.