Overview of Helicobacter Pylori Infection

Helicobacter pylori (commonly shortened to H. pylori) are spiral-shaped bacteria that can attach to the lining of the stomach or small intestine and thrive and multiply in that environment. H. pylori infection occurs when the bacteria release toxins.

Helicobacter pylori infection is the leading cause of stomach ulcers (e.g., peptic ulcers) and gastritis (inflammation in the stomach). Approximately 80–95 percent of people with ulcers are infected with H. pylori. Treatment usually is quite effective. Ulcers often heal completely, resulting in a lower risk for recurrence. Left untreated, H. pylori infection can lead to stomach cancer.

Types of Helicobacter Pylori Infection

There are a number of different strains of H. pylori bacteria, which may influence the way the infection is treated. Some strains of the bacteria have become resistant to certain treatment therapies. Different strains of the bacteria are found in different parts of the world and physicians take this into account when considering treatment options.

Incidence and Prevalence of Helicobacter Pylori Infection

The presence of H. pylori bacteria is common. According to some researchers, about half of the world's population may be affected. Approximately 90 percent of these people do not experience problems, according to the American Academy of Family Physicians.

Helicobacter pylori infection rates vary throughout the world. In industrialized areas, the infection rate is between 20 and 30 percent. In developing countries, up to 70 percent of people may be infected. In the United States, about half of people over the age of 60 and 20 percent of people under the age of 40 are infected, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). This may be due to recent improvements in sanitation measures.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 28 Feb 2008

Last Modified: 18 Sep 2015