Seroprevalence of Helicobacter pylori infection and gastric mucosal atrophy in Bhutan, a country with a high prevalence of gastric cancer

Gastric cancer is the second leading cause of cancer-related mortality in the world. Recently, serum Helicobacter pylori antibodies and pepsinogen (PG) have been used for gastric cancer screening. The incidence of gastric cancer in Bhutan is reported to be quite high compared with that in neighbouring countries. In this study, 381 subjects from three areas of Bhutan were assessed for gastric mucosal atrophy and serological parameters. Anti-H. pylori IgG, PG I, PG II and cytotoxin-associated gene A (CagA) antibodies were measured using ELISA. Subjects were classified into four groups according to H. pylori and PG seropositivity: Group A (H. pylori-negative/PG-negative), Group B (H. pylori-positive/PG-negative), Group C (H. pylori-positive/PG-positive) and Group D (H. pylori-negative/PG-positive). The prevalence of H. pylori in the 381 subjects was 71.1 % (271/381), with high infection rates found in rural areas. The PG I/II ratio was significantly inversely correlated with the atrophy score in the antrum and the corpus (P<0.001). Multivariate analysis showed that the PG status was significantly associated with the presence of atrophy in the corpus. The prevalence of the PG-positive status was significantly higher among H. pylori-positive subjects than among H. pylori-negative subjects (P<0.001). Based on the ABC method, Group B was the most dominant, followed by Group A, Group C and Group D. The high incidence of gastric cancer in Bhutan can be attributed to the high prevalence of H. pylori infection and gastric mucosal atrophy.