Chronic gastritis is one of the most common diseases in the world.
The recognition of Helicobacter pylori as the major causative agent of chronic gastritis, gastric ulcer disease, and stomach cancer has spawned intensive research on the pathophysiology and epidemiology of this organism. H. pylori has been classified as a Class I carcinogen by the World Health Organization. In spite of the widespread occurrence of the diseases attributable to the organism, little is known about the mode of transmission and microbial ecology of H. pylori . Current opinion regarding the mode of transmission of H. pylori is divided with some epidemiological evidence supporting the hypothesis of direct transmission and other studies implicating a water-borne transmission route. Unfortunately, there is little data concerning the occurrence and persistence of this organism in surface and ground water or the efficacy of water disinfection practices for controlling this organism.