FRI Briefings Helicobacter pylori

Gastrointestinal diseases Urticaria Summary References January 1997 Update to Helicobacter pylori Briefing Gastrointestinal diseases Ulcer treatment has been revolutionized by recently discovered knowledge about Helicobacter pylori, a bacterium commonly found in the human gastrointestinal tract. These bacteria were originally thought to be a species of Campylobacter, but a later, more thorough examination revealed that they were different enough to be assigned to a new genus. Current evidence indicates that H. pylori is associated with Type B gastritis (a persistent inflammation of the stomach involving the loss of normal gastric glands), ulcers, and gastric cancer. In most cases, eradication of these bacteria leads to a long-term improvement in symptoms of gastritis and ulcers. As yet there is very little information on actual modes of transmission of this organism, but its presence in the stomach suggests that H. pylori may be food-or waterborne (from fecal contamination). It may also be expelled during vomiting and then, under unhygienic conditions, be acquired by a new host. This update on Helicobacter pylori will summarize and discuss recent discoveries relevant to the pathogenicity and acquisition of this bacterium. Although much research has been devoted to determining how Helicobacter infections are acquired, the simple answer is that, with the exception of a few patients who have been infected during gastric endoscopy, we don't know how this organism is introduced into the stomach. However, once an infection has been established, it apparently persists indefinitely. Prevalence of infection in different populations today varies greatly, with reports of 50–90% of people in developing countries of Asia, Africa, and South America carrying H. pylori whereas a lower prevalence exists in industrialized countries. However, within all countries, those in lower socioeconomic groups (who typically have a less nutritious diet and live in less sanitary conditions) and persons who live in institutions are more likely to be infected than their better-off compatriots (1). It appears that most infections are acquired during childhood. Data from a cohort of Ethiopian children demonstrated that by age 4, 60% of them already had been exposed to these bacteria, as demonstrated by the presence of antibodies to H. pylori. By 12 years of age, nearly 100% had seroconverted. Among Swedish children, the sharpest rise in prevalence was between the ages of 9 and 10, with 20% of children infected by age 10 (2). Adults in developed countries continue to acquire H. pylori but at a very low rate: …