What are the indications for testing Helicobacter pylori (H. pylori)?

Indications for Testing Helicobacter pylori

H. pylori testing is indicated primarily for patients with active peptic ulcers, history of ulcers, gastric MALT lymphoma, uninvestigated dyspepsia in patients under 50 years without alarm symptoms, and after eradication therapy to confirm successful treatment. 1, 2, 3

Primary Indications for H. pylori Testing

• Active peptic ulcer disease - All patients with active gastric or duodenal ulcers should be tested for H. pylori infection 3
• History of documented peptic ulcer disease - Even if currently asymptomatic, patients with past ulcers should be tested 3
• Gastric MALT lymphoma - Testing is essential as H. pylori eradication is a primary treatment 3
• Uninvestigated dyspepsia in patients <50 years without alarm symptoms - The "test and treat" strategy is recommended to reduce unnecessary endoscopies 1, 2
• Family history of gastric cancer - These patients may benefit from testing due to increased risk 3
• After eradication therapy - To confirm successful treatment, especially in patients with complicated ulcer disease or persistent symptoms 3, 4

Situations Requiring Endoscopy and Invasive Testing

• Patients with alarm symptoms - Including bleeding, weight loss, dysphagia, palpable mass, or malabsorption 1, 2
• Older patients (≥50 years) with new-onset dyspepsia - Due to increased risk of malignancy 1
• Patients who have failed eradication therapy - Especially when culture and antimicrobial sensitivity testing are needed to guide subsequent treatment 1
• Regions with high clarithromycin resistance - Culture and susceptibility testing should be performed before first-line treatment if standard clarithromycin-containing triple therapy is being considered 1

Recommended Testing Methods

Non-invasive Tests (Preferred for Initial Diagnosis)

• Urea Breath Test (UBT) - Highest accuracy among non-invasive tests with sensitivity of 94.7-97% and specificity of 95-95.7% 5, 2
• Stool Antigen Test - Comparable accuracy to UBT with sensitivity and specificity around 93% 2, 6
• Serology - Not recommended as primary diagnostic method due to inability to distinguish between active infection and past exposure 2

Invasive Tests (Requiring Endoscopy)

• Rapid Urease Test - Quick results during endoscopy 1
• Histology - Allows visualization of bacteria and assessment of mucosal damage 1
• Culture - Permits antimicrobial susceptibility testing, especially valuable after treatment failure 1
• PCR - Can detect H. pylori and antibiotic resistance directly from biopsies 1

Important Considerations and Pitfalls

• Proton pump inhibitors (PPIs) - Can cause false-negative results in all tests except serology; should be discontinued at least 2 weeks before testing 1, 2
• Antibiotics and bismuth compounds - Should be stopped at least 4 weeks before testing 2
• Post-treatment testing - Should be performed at least 4 weeks after completion of therapy 4
• Serological testing limitations - Cannot distinguish between active and past infection; antibodies remain elevated for months after eradication 2
• Test selection in special populations - Children and pregnant women should avoid radioactive 14C-UBT but can safely undergo 13C-UBT 1

Clinical Decision Algorithm

1. Patient <50 years with dyspepsia, no alarm symptoms:

   • Use non-invasive test (UBT or stool antigen test)
   • If positive, treat for H. pylori 1, 2

2. Patient ≥50 years with new-onset dyspepsia OR any patient with alarm symptoms:

   • Refer for endoscopy with biopsy-based testing
   • If H. pylori positive, treat accordingly 1

3. Patient with history of peptic ulcer:

   • Test for H. pylori if not previously tested/treated
   • Use non-invasive test if no current symptoms
   • Consider endoscopy if symptoms persist 3, 4

4. Post-treatment confirmation:

   • Use UBT or stool antigen test (not serology)
   • Test at least 4 weeks after completing therapy 2, 4