Pathogenesis of Helicobacter pylori Infection.

As with many infectious diseases, only a fraction of people infected with Helicobacter pylori develop clinical disease, and host genetics, host immune response, and bacterial virulence factors appear to play critical roles. There has been considerable interest in putative bacterial virulence factors and, while several have been identified, it is not clear whether they act independently or in concert. Disease associations have been proposed for the cag pathogenicity island (PAI), vacA, and genes encoding outer membrane proteins (OMPs). Numerous studies published in the last year have provided new insights into the function of these putative virulence factors in gastroduodenal pathogenesis. This article will review the recent novel findings (from April 2004) for the roles of the putative disease-associated virulence factors as well as their interaction with host.