Helicobacter pylori in water sources: a global environmental health concern.

Helicobacter pylori are Gram-negative micro-aerophilic motile curve rods that inhabit the gastric mucosa of the human stomach. The bacterium chronically infects billions of people worldwide and is one of the most genetically diverse of bacterial species. More than half of the world population in both developed and developing countries are infected with this organism. Infection usually occurs without overt clinical symptoms, particularly in poor communities. If untreated, the infection can last for decades without causing symptoms. In some communities, however, infection with the organism causes peptic and duodenal ulcers, gastritis, duodenitis, and gastric cancers. How H. pylori initially enters the stomach is not known, but contaminated food particles and water are suspected, with the former physically shielding it from stomach acid. Similarly, the route of transmission of this pathogen is unknown. Several reports have suggested the possibility of waterborne transmission as the organism can survive for a few days in fresh cold water, salt water, distilled water, and tap water. Knowledge of the epidemiology and mode of transmission of H. pylori is important to prevent its spread and may be useful in identifying high risk populations.