Helicobacter pylori gastritis
Helicobacter pylori is the most common cause of chronic gastritis, with a prevalence that corresponds to socioeconomic status. In developing countries, most members of the population are infected. In Canada, 20% of those under 40 years of age are infected, and 50% over 50. In Canada, the prevalence is increased in minorities and in immigrants from countries with higher prevalence.
Virtually everyone who is infected develops chronic gastritis, which rarely if ever resolves spontaneously. The gastritis is known as chronic active gastritis, as it is characterized by both chronic inflammation (lymphocytes and plasma cells) and acute inflammation (neutrophils).
H. pylori can be detected by a variety of tests including serology, tests based on the detection of the bacterial urease, and direct visualization in biopsy samples examined by the pathologist (the gold standard for detection). The non-invasive tests are useful in assessing younger patients or those who do not have additional "alarm symptoms" such as weight loss.
Assessment of biopsies is important for older patients or those with "alarm symptoms", as this allows not only the diagnosis to be made, but also allows for assessment of the gastric mucosa for any complications of H. pylori infection, especially cancer. Treatment of uncomplicated infection is readily accomplished with a combination of antibiotics (such as clarithromycin) and other drugs (usually including a proton pump inhibitor).