H. pylori  is a Gram-negative, microaerophilic, spherical bacteria that often resides in the mucous layer of the antral and fundal gastric epithelium, and occasionally in ectopic gastric tissue in the duodenum or esophagus. First isolated from humans in 1982, H. pylori  protects itself from the acidic environment of the stomach by residing in the mucous layer of the stomach and also by producing the enzyme urease that breaks down urea into ammonium salts, which serve as a buffer against gastric acidity. H. pylori  is highly motile due to the function of its flagella, which enable the organism to move within the mucous layer of the stomach.

H. pylori  is found in individuals in most areas of the world, but its prevalence is linked to specific geographic region, age, ethnicity and socioeconomic status. Studies frequently suggest that transmission of H. pylori  occurs via fecal-oral and oral-oral routes. In many developing countries, H. pylori  colonization is almost universal by age 20, likely due to population crowding and substandard water sanitation. In the United States, prevalence increases with age.

H. pylori  is found in 90 percent of patients with duodenal ulcers and in 70 to 90 percent of patients with gastric ulcers. H. pylori  infection in fact is the most common cause of non-NSAID-related or non-aspirin-related peptic ulcer disease. Approximately 10 to 20 percent of individuals infected with H. pylori  will eventually develop peptic ulcer disease. Other serious complications of infection include:

• Atrophic gastritis

• Gastric adenocarcinoma

• Gastric lymphoma

Up to 70 percent of individuals infected with H. pylori  experience long periods of presenting very minimal or no symptoms. Prompt detection of  H. pylori  and appropriate intervention and eradication is necessary to minimize the potentially serious complications of infection.

Ulcer disease usually presents symptoms, including: 

• Gnawing or burning epigastric pain

• Nausea

• Vomiting

• Weight loss

• Bloating

• Belching

• Heartburn