What is the recommended diagnosis and treatment for Helicobacter pylori (H pylori) infection?

Diagnosis and Treatment of Helicobacter pylori Infection

The recommended approach for H. pylori diagnosis is to use non-invasive tests such as the urea breath test (UBT) or stool antigen test for initial diagnosis, followed by triple therapy consisting of amoxicillin 1g, clarithromycin 500mg, and lansoprazole 30mg, all given twice daily for 14 days. 1, 2

Diagnostic Testing

Non-invasive Testing (Preferred)

• Urea Breath Test (UBT):

  • Gold standard for non-invasive diagnosis with high sensitivity and specificity
  • Must discontinue PPIs for 2 weeks before testing to avoid false negatives 1, 3
  • Ideal for initial diagnosis and confirming eradication after treatment

• Stool Antigen Test:

  • Excellent alternative when UBT is unavailable
  • Also requires cessation of PPIs, bismuth, and antibiotics for 2 weeks prior 1
  • Particularly useful for follow-up testing after treatment

• Serology (IgG antibody testing):

  • Limited utility due to inability to distinguish between active and past infection
  • Only use when patients cannot stop PPIs or have recently taken antibiotics
  • Moderate sensitivity (85%) but limited specificity (79%) 3
  • Not recommended for confirming eradication as antibodies persist after treatment 1

Invasive Testing (Endoscopy with biopsy)

• Reserved for specific clinical scenarios:

  • Patients with alarm symptoms (bleeding, weight loss, anemia)
  • Older patients (>45-55 years) with new-onset dyspepsia
  • Patients who have failed eradication therapy and need antimicrobial sensitivity testing 1
  • When gastric cancer or MALT lymphoma is suspected 4

• Biopsy-based tests:

  • Histology with immunohistochemistry (most accurate)
  • Rapid urease test
  • Culture (allows antimicrobial susceptibility testing)

Treatment Regimens

First-line Treatment

• Triple Therapy (FDA-approved):

  • Amoxicillin 1g twice daily
  • Clarithromycin 500mg twice daily
  • Lansoprazole 30mg twice daily
  • Duration: 14 days 2

• Alternative for clarithromycin-resistant areas (≥15% resistance):

  • Bismuth Quadruple Therapy: Bismuth salt, PPI, tetracycline, and metronidazole for 14 days 4
  • Concomitant Therapy: PPI, amoxicillin, clarithromycin, and metronidazole for 14 days 4

• For penicillin-allergic patients:

  • Dual Therapy: Lansoprazole 30mg three times daily and amoxicillin 1g three times daily for 14 days (if allergy is not severe) 2
  • Bismuth Quadruple Therapy (without amoxicillin): Bismuth salt, PPI, tetracycline, and metronidazole 5

Second-line Treatment

• If first-line therapy fails:
  • Levofloxacin Triple Therapy: PPI, amoxicillin, and levofloxacin for 14 days
  • Bismuth Quadruple Therapy (if not used as first-line) 4

Post-Treatment Evaluation

• Confirm eradication at least 4-8 weeks after completing therapy
• Use UBT or stool antigen test (not serology) 1, 6
• Stop PPIs for at least 2 weeks before testing

Special Considerations

High-Risk Populations for Testing

• Patients with active or past peptic ulcer disease
• First-degree relatives of gastric cancer patients
• Populations with high H. pylori prevalence (e.g., Latino, African American, East Asian in the US) 1
• Patients with unexplained iron deficiency anemia or vitamin B12 deficiency 4
• Patients on long-term NSAIDs or aspirin 4

Common Pitfalls to Avoid

1. Using serology to confirm eradication (remains positive long after successful treatment)
2. Testing too soon after treatment (wait at least 4 weeks)
3. Failing to stop PPIs before non-invasive testing (causes false negatives)
4. Using inadequate treatment duration (14 days is superior to shorter courses) 7
5. Not considering local antibiotic resistance patterns when selecting therapy

By following this evidence-based approach to diagnosis and treatment, clinicians can effectively manage H. pylori infection and reduce the risk of associated complications including peptic ulcer disease and gastric cancer.