Helicobacter pylori

 

Clinical Background

Previously known as Campylobacter pylori, Helicobacter pylori (H. pylori) is one of the most common bacterial pathogens in humans.

Epidemiology

  • Prevalence – depends on age, socioeconomic status and ethnic group
    • Approximately 35% in U.S. population
    • Highest prevalence – lower income, non-Caucasian population
    • Lowest prevalence – middle to upper income, Caucasian population
  • Transmission – probably fecal-oral

Organism

  • H. pylori is a gram-negative, spiral-shaped, urease-positive, microaerophilic bacterium that infects the gastric epithelium
  • Causes chronic inflammation in most infected hosts, up to one-half of the world's population  
  • Implicated as risk factor for gastric adenocarcinoma and gastric B-cell lymphoma

Risk Factors

  • Socioeconomic status – highest in lower income, non-Caucasian population
  • Age – lowest in young children
  • Ethnicity – lowest in Caucasians

Clinical Presentation

  • Dyspepsia – chronic and recurrent pain or discomfort centered in the upper abdomen (epigastrium)
  • Gastritis
  • Abdominal pain
  • Peptic ulcer disease – gastric, duodenal
  • Cancer
    • Gastric mucosa-associated lymphoid tissue lymphoma (MALT)
    • Gastric cancer

Treatment

  • Test and treat strategy is recommended for patients with uninvestigated persistent dyspepsia by the American College of Gastroenterology (Chey 2007) for patients <45 years of age who have none of the following “alarm” symptoms
    • Bleeding
    • Anemia
    • Early satiety
    • Unexplained weight loss
    • Progressive dysphagia
    • Odynophagia
    • Recurrent vomiting
    • Family history of upper gastrointestinal cancer
    • Previous esophogastric malignancy
  • Eradication of bacteria recommended in the following
    • H. pylori-related ulcers
    • Gastric B-cell lymphomas
    • Patients with family history of gastric cancer