The discovery and concept that Helicobacter pylori is associated with gastric disease including gastric cancer which is one of the most common and frequently lethal forms of malignancy, heralded a new and rapidly expanding field recognizing the emergence of many new pathogens and disease syndromes in clinical medicine, as well as basic infectious disease research. There is now an extensive and widely known literature of how H. pylori is involved in a wide variety of disease syn dromes. As summarized in the introductory chapter of this volume, many major advances have been made in diagnosis,...