What is Helicobacter pylori?

H. pylori is a bacterium that causes chronic inflammation of the inner lining of the stomach and the duodenum (the first part of the small intestine). This bacterium survives the acidic environment of the stomach by living in the mucous lining.

Ninety percent of duodenal ulcers are believed to be caused by H. pylori1. One in six individuals carrying this bacterium will go on to develop ulcers of the duodenum or stomach2. Those infected are also at a higher risk of stomach cancer2.

Fortunately, H. pylori can be easily diagnosed with the proper screening tools and can be treated with antibiotics.

Prevalence of H. pylori

Half of the world’s population is believed to be infected with H. pylori3 4. This makes it the most widespread bacterial infection in the world. Actual infection rates vary from country to country. Developing countries have a much higher rate of infection than the Western world. Higher standards of hygiene and widespread use of antibiotics are believed to be reason for the discrepancy in prevalence rates.

Up to 30 % of the Canadian population is infected, with higher prevalence rates found among immigrants from less developed nations. In South East Asia, infection rates can mount to 70 % of the population.

If you’re concerned about H. pylori infection or think you may have a high risk of stomach cancer, talk to your doctor. Together you can decide whether you may benefit from H. pylori screening.

Causes of H. pylori

H. pylori is believed to be transmitted orally, especially from ingestion of tainted food or water. It has also been suggested that person to person contact can facilitate transmission. H. pylori bacteria enter your body through your mouth and passes into your digestive system. Stomach acids make for a hostile environment for many bacteria. But the H. pylori bacterium is especially well-adapted for survival in the stomach. It produces an enzyme that, through a series of biochemical processes, creates a low-acid buffer zone for itself.


Most cases of H. pylori infection are asymptomatic. Signs or symptoms that can occur with H. pylori infection include :

  • Ache or burning pain in your abdomen
  • Nausea
  • Vomiting
  • Frequent burping
  • Bloating
  • Weight loss

Seek immediate medical help if you experience :

  • Severe or persistent abdominal pain
  • Difficulty swallowing
  • Bloody or black tarry stools
  • Bloody or black vomit or vomit that looks like coffee grounds
  1. Sherman P, et al. Canadian Helicobacter Study Group Concensus Conference on the Approach to Helicobacter pylori Infection in Children and Adolescents 1999; Available from : http://www.cag-acg.org/uploads/guidelines/H%20pylori%20consensus%20children%201999.pdf.
  2. Lee Denis and M. Jay. Helicobacter Pylori. Medicine Net; Available from : http://www.medicinenet.com/helicobacter_pylori/discussion-191.htm.
  3. Mayo Clinic. H. pylori infection. 2009; Available from : http://www.mayoclinic.com/health/h-pylori/DS00958.
  4. Nugent, C. What is Helicobacter Pylori? 2010; Available from : http://diseases-viruses.suite101.com/article.cfm/what-is-helicobacter-pylori