Helicobacter pylori

What is Helicobacter pylori?

Helicobacter pylori ( H. pylori ) is a spiral shaped bacterium. It lives in the mucus layer of the stomach, which sticks to the stomach lining.

What illnesses does H. pylori cause?

Most people who are infected with H. pylori do not have any symptoms and will never develop illness as a result of the infection. Some people, however, develop ulcers in the stomach (gastric ulcers) or in the duodenum (duodenal ulcers) which is part of the small intestine that links the stomach to the large intestine. H. pylori is the most important cause of such ulcers.

Aspirin and drugs used for the treatment of arthritis are another important cause of ulcers and ulcer complications.

Certain stomach cancers are two to six times more common (though still very rare) in people who are infected with H. pylori compared with people who are not infected.

How do people acquire H. pylori?

We do not know how H. pylori infection spreads, or why some people develop illness although most people do not. The bacteria probably spread from one person to another through close contact in early childhood, such as kissing, or through poor hygiene as the bacteria may be passed in stools. It has been suggested that contaminated food or water may be sources of infection, but the evidence is not conclusive.

How common is H. pylori infection?

H. pylori infection is found throughout the world. Most people acquire their infection in early childhood. The average age at which people acquire infection is lower in developing countries.

Of those who have not picked up the bacteria by the time they reach adulthood, about 1 to 3% of adults acquire the infection each year. In the United Kingdom, over half of people aged 50 years or over are infected with H. pylori.

For most people, once the infection is acquired it persists without treatment.

Diagnosing H. pylori infection.

Diagnostic Methods

There are several methods for detecting H. pylori. Your doctor will discuss the test(s) that are appropriate for you.

Blood tests
Blood samples from patients are tested to see if they contain antibodies to H. pylori. If antibodies are present, they indicate that the patient has been infected.
Biopsy tests
Small samples of the lining of the stomach or duodenum are collected by a tube passed down through the mouth. The samples are either examined by microscopy to see if H. pylori bacteria are present, or they are incubated to grow H. pylori bacteria.
Breath tests
These are usually used to assess the effectiveness of treatment. The patient is given a drink containing a chemical that can be digested by H. pylori. The chemical has a marker attached to it. If H. pylori bacteria are present in the gut, they digest the chemical and break off the marker, which is absorbed through the gut and into the blood and released into the lungs. Patients breathe in to a bag, and the gases are analysed to see if they contain the marker. If H. pylori bacteria are not present in the gut, the chemical is not digested and the marker cannot get into the body and reach the lungs.
Faecal Antigen tests
These tests are for evidence of H. pylori in the stools.

Treatment to eradicate H. pylori

Combinations of antibiotics are used to eradicate H. pylori. It is important that the course of treatment is completed.

Who should be treated?

People with active ulcers or a documented history of ulcers should be tested for H. pylori, and those who are found to be infected should be treated.

For patients with 'heartburn'/indigestion and no evidence of an actual ulcer, the benefits of treating H. pylori infection are unclear.

Are there any long-term consequences of H. pylori infection?

Recent studies have shown an increased risk of stomach cancer in people with long-term infection with H. pylori. In developed countries, the proportion of people infected with H. pylori has fallen, and gastric and duodenal ulcers and stomach cancer have become less common.

What can people do to prevent H. pylori infection?

There are no specific recommendations for avoiding H. pylori because the source(s) of infection are not known. General advice for avoiding gastrointestinal infections should be followed. This includes washing hands thoroughly after going to the toilet, eating food which has been properly prepared, and drinking water from a safe, clean source. There is no likelihood of a vaccine in the near future.

What is the Health protection Agency doing about this infection?

The Health Protection Agency is involved in testing for H. pylori infection, monitoring trends in numbers of infected people, and monitoring trends in resistance to the antibiotics that are used to treat infected people.

There is a Health Protection Agency Reference Unit for Helicobacter, and the Health Protection Agency collaborates with clinicians and researchers who work on H. pylori to advise on treatment/testing guidelines.

Last reviewed: 8 May 2009