Helicobacter pylori Infection

What is Helicobacter pylori?

Helicobacter pylori (H. pylori) is a type of bacteria that lives in the stomach lining. It can cause inflammation and lead to various gastrointestinal conditions, including inflammation of the stomach lining, ulcers, and, in some cases, stomach cancer.

H. pylori infection is extremely common, with more than half of the world’s population carrying the bacteria. In Australia, it is estimated that around 30% of adults are infected. Most people acquire the infection in early childhood. It is more common among Aboriginal and/or Torres Strait Islander people and in individuals from developing countries.

What are the symptoms of H. pylori infection?

Many people with H. pylori infection experience no symptoms at all. However, when symptoms do occur, they may include:

  • Upper abdominal pain or discomfort (which may improve or worsen with eating)

  • Indigestion or upset stomach

  • Bloating or excessive burping

  • Nausea and vomiting

  • Loss of appetite or unintentional weight loss

  • Gastrointestinal bleeding (bloody or black stools, vomit containing blood, or vomit that resembles coffee grounds)

  • Iron deficiency, with or without anaemia

What are the complications of H. pylori infection?

H. pylori infection is associated with several gastrointestinal conditions, including:

  • Gastritis: Inflammation of the stomach lining

  • Duodenitis: Inflammation of the first part of the small intestine (duodenum)

  • Peptic ulcers: A leading cause of stomach and duodenal ulcers, which can lead to gastrointestinal bleeding or perforation in severe cases

  • Stomach cancer: Long-term H. pylori infection increases the risk of gastric (stomach) cancer, although this is uncommon

  • MALT lymphoma: A rare type of slow-growing cancer that affects the immune cells in the stomach lining.

How is H. pylori transmitted?

H. pylori is primarily transmitted from person to person through:

  • Direct contact with saliva, vomit, or stool from an infected person

  • Consumption of contaminated food or water

  • Poor hygiene practices

How is H. pylori diagnosed?

H. pylori infection can be diagnosed using several methods:

  • Urea breath test: A painless, non-invasive test that detects carbon dioxide in expired air, produced as a by-product of the enzyme urease, which H. pylori produces

  • Stool antigen test: Detects H. pylori proteins in a stool sample

  • Blood test: Measures antibodies against H. pylori but is less commonly used, as it does not distinguish between past and current infections

  • Gastroscopy with biopsy: A small tissue sample is taken from the stomach lining during an endoscopy to confirm the presence of H. pylori

How is H. pylori treated?

H. pylori is treated with a combination of medications for 1-2 weeks, including:

  • A proton pump inhibitor (PPI): Reduces stomach acid to promote healing (e.g., esomeprazole, pantoprazole, omeprazole)

  • A combination of antibiotics: typically clarithromycin plus amoxicillin or metronidazole

Standard therapy is effective in most cases, but approximately 25–30% of people may have persistent infection and require further treatment. In such cases, alternative treatment may include a different combination of antibiotics (often containing levofloxacin) or bismuth-based therapy, which is available from compounding pharmacies.

What happens after treatment?

A follow-up test (usually a urea breath test) is recommended at least four weeks after completing treatment to confirm eradication of the infection. It is important to wait four weeks because recent use of acid-suppressing drugs or antibiotics can interfere with the accuracy of the test.

In Australia, routine screening of family contacts for H. pylori infection is not generally required.