Helicobacter pylori is a curved mlcroaerobic bacterium that was first lsolated from human antral gastric biopsy material in 1982 by Marshall and colleagues in Perth, Western Australia (1). Since then, enormous interest has developed in the micro-organism that now appears to be one of the most common human bacterial pathogens, estimated to be infecting at least one third of the world population (2). Although most Individuals appear to be asymptomatic H. pylon is implicated as a key risk factor in a number of gastrointestinal diseases, including duodenal and gastric ulceration and gas- tric cancer (3). Most clinical and basic research aspects have been exten- sively reviewed (4), but some key features of the general epidemlology of H pylon infections are as follows: