By Christopher S. Cutler, M.D.
- 1) What is Helicobacter pylori? Helicobacter pylori (H. pylori) is one of the most common bacterial infections in the world, present in half of the population. The prevalence of H. pylori is generally lower in the United States than in many other parts of the world. It is more common in African Americans and Hispanics than in Caucasians. H. pylori is found in the stomach and is a very common cause of peptic ulcer disease.
2) How is it spread? The route by which the infection is spread is unknown. People could be infected by contaminated water in developing countries. Person to person transmission probably also occurs. The infection is usually acquired in childhood. Risk factors include low socioeconomic status, increasing number of siblings, and having an infected parent. Reinfection is rare, seen in less than 2% of persons per year. A repeat positive test for H. pylori usually signifies a recurrence of the bacteria which was not adequately treated.
3) What can H. pylori infection lead to? pylori infection may cause:
• peptic ulcer disease
• chronic gastritis
• gastric cancer
• gastric MALT lymphoma.
4) What are common symptoms of H. pylori? Symptoms that patients experience are usually from an ulcer caused by H pylori. These can include: upper abdominal pain, bloating, feeling full after a small meal, poor appetite, nausea and vomiting, intestinal bleeding, and fatigue from anemia.
5) Who should be tested for H. pylori? There is no reason for universal screening in North America. The following conditions warrant testing for H. pylori:
• active peptic ulcer disease
• a past history of peptic ulcer disease if cure of H. pylori has not been documented
• low grade gastric MALT lymphoma
• early gastric cancer resected during an endoscopy
• dyspepsia (upper abdominal pain) in people younger than 60 years old with no other worrisome symptoms
• prior to starting chronic treatment with NSAIDs or low-dose aspirin
• unexplained iron deficiency anemia
• idiopathic immune thrombocytopenia in adults
6) What tests can be performed to diagnose H. pylori?
• upper endoscopy with stomach biopsies – shows active infection, sensitivity of 95%
• urea breath test – shows active infection, sensitivity up to 95%
• stool antigen test – shows active infection, sensitivity of 94%
• blood test for H. pylori antibody – this can’t distinguish between active and past infection
7) What interferes with testing for H. pylori? The following may decrease the sensitivity of H. pylori tests:
• active bleeding from an ulcer
• use of a proton pump inhibitor (Prilosec) within 1-2 weeks of testing
• bismuth or antibiotic use within 4 weeks of testing.
8) How is H. pylori treated? All patients with documented H. pylori infection should be offered therapy.
• Triple therapy consists of: a proton pump inhibitor twice daily, amoxicillin 1 gram twice daily, and clarithromycin 500 mg twice daily, all for 14 days. Eradication rates are approximately 80% with this regimen. If the patient is allergic to penicillin, metronidazole 500 mg three times daily can be substituted for amoxicillin. Previous exposure to clarithromycin reduces the efficacy of this regimen.
• Quadruple therapy consists of: a proton pump inhibitor twice daily, bismuth subsalicylate 300 mg 4 times daily, metronidazole 250 mg 4 times daily, and tetracycline 500 mg 4 times daily, all for 14 days. Eradication rates are approximately 91% with this regimen.
• There are multiple other drug regimens, utilizing antibiotics such as levofloxacin, that may be used depending on antibiotic resistance and prior response to the above.
9) Should patients be tested to prove eradication of H. pylori? Yes, especially because of increasing antibiotic resistance. This can be done with gastric biopsies during an endoscopy, with a urea breath test, or with stool antigen testing. Patient should be off of proton pump inhibitors for 1-2 weeks and off of bismuth and antibiotics for 4 weeks prior to testing. If someone has failed 2 courses of antibiotics, consideration should be given to an endoscopy with gastric biopsies for H. pylori culture and sensitivity.
10) Who is Barry Marshall? Barry Marshall is an Australian physician who won the Nobel Prize in Medicine for his discovery of Helicobacter pylori and its role in gastritis and peptic ulcer disease. This was one of my favorite stories in medical school. Dr. Marshall had an endoscopy performed which was normal. He then drank a broth of H. pylori bacteria. A few days later he developed nausea, vomiting, bloating, and bad breath. On day 8 he had a repeat endoscopy showing severe gastritis and a biopsy showing that the H. pylori had colonized his stomach. His work changed the perception that ulcers were simply due to stress.
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