Helicobacter pylori

Infectious Agent

Helicobacter pylori is a small, curved, microaerophilic, gram-negative, rod-shaped bacterium.


Believed to be mainly fecal-oral or possibly oral-oral.


About two-thirds of the world’s population is infected, but it is more common in developing countries.

Clinical Presentation

Usually asymptomatic, but H. pylori is the major cause of peptic ulcer disease and gastritis worldwide, which present as gnawing or burning epigastric pain. Less commonly, symptoms include nausea, vomiting, or loss of appetite. Infected people have a 2- to 6-fold increased risk of developing gastric cancer and mucosal-associated-lymphoid-type (MALT) lymphoma compared with their uninfected counterparts.


Fecal antigen assay, urea breath test, rapid urease test, or histology of biopsy specimen. A positive serology indicates present or past infection.


Asymptomatic infections do not need to be treated. Patients with active duodenal or gastric ulcers should be treated if they are infected. Treatment should be determined on an individual basis. Standard treatments are clarithromycin triple therapy (proton pump inhibitor [PPI] + clarithromycin + amoxicillin or metronidazole) or bismuth quadruple therapy (PPI or H2-blocker + bismuth + metronidazole + tetracycline). See www.acg.gi.org/physicians/guidelines/ManagementofHpylori.pdf.


No specific recommendations.


  1. Chey WD, Wong BC. American College of Gastroenterology guideline on the management of Helicobacter pylori infection. Am J Gastroenterol. 2007 Aug;102(8):1808–25.  [PMID:17608775]
  2. Lindkvist P, Wadstrom T, Giesecke J.Helicobacter pylori infection and foreign travel. J Infect Dis. 1995 Oct;172(4):1135–6.  [PMID:7561197]
  3. Peterson WL, Fendrick AM, Cave DR, Peura DA, Garabedian-Ruffalo SM, Laine L.Helicobacter pylori -related disease: guidelines for testing and treatment. Arch Intern Med. 2000 May 8;160(9): 1285–91.  [PMID:10809031]


Ronnie Henry, Bradley A. Connor