Is there another chapter in the Helicobacter pylori/peptic ulcer disease story?

The role of Helicobacter pylori in the production of mucosal damage has largely been considered within a simple infection paradigm, because to date eradication has appeared to be a predictable outcome of antibiotic therapy. Changes in the epidemiology and management of peptic ulcer disease, however, require a more comprehensive framework to understand these shifting clinical patterns. The present review examines mucosal damage as an outcome of a complicated host-parasite relationship, with alterations in both parasite physiology and host defence mechanisms being keys to understanding disease patterns.