Previously classified as a type B gastritis. Histological gastritis is almost always present if helicobacter is present. H. pylori infection is carries a significant risk for the development of atrophic gastritis and intestinal metaplasia. Also it appears to have a causative role in gastric carcinogenesis.
- in the developed world it is more common in the older age-groups, and this may imply a cohort effect
- once established H. pylori infection is generally life- long unless either the organism is eradicated, or, the severity of the gastritis makes the microenvironment inhospitable for the bacteria e.g. intestinal metaplasia