Prevalence and heterogeneity of Helicobacter pylori in gastric biopsies of patients with gastroduodenal diseases.

Helicobacter pylori is a risk factor for development of peptic ulcers and adenocarcinoma of distal stomach. There are several highly specialized virulence factors, such as the production of sialic acid-specific hemagglutinins, cytotoxins and enzymes. This study was designed to study the in vivo prevalence of H. pylori in patients with gastroduodenal diseases, the in vivo correlation between H. pylori infection and blood group O, and the heterogeneity of H. pylori isolates in central Taiwan. We enrolled 776 symptomatic patients residing in the central Taiwan area. The age-specific in vivo prevalence of H. pylori in patients with gastroduodenal diseases increased from 11.1% in those between the ages of 1 to 20, 73.1% in those between the ages of 21 and 30, and to 79.8% in those between the ages of 51 and 60. In conclusion, H. pylori was present in 70% of biopsied specimens of symptomatic patients with gastroduodenal diseases and had the highest incidence (86%) in patients with peptic ulcers. The prevalence of H. pylori cag A expression positive strains in central Taiwan was 92.5%. This study has also demonstrated the high correlation between H. pylori and the blood group O-positive patients with gastroduodenal diseases. The prevalence of H. pylori infection in blood O-positive patients in central Taiwan was 86.4%.