What is the recommended testing and treatment approach for a patient presenting with symptoms suggestive of H pylori (Helicobacter pylori) infection, such as dyspepsia or peptic ulcer disease, with potential risk factors for complications?

H. Pylori Testing: Recommended Approach

For patients under 50-55 years with dyspepsia and no alarm symptoms, use non-invasive testing (urea breath test or stool antigen test) and treat immediately if positive without requiring endoscopy. 1, 2, 3

Who Should Be Tested

Strong Indications (Test All These Patients)

• Active or past peptic ulcer disease (gastric or duodenal ulcers) 1, 3
• Uninvestigated dyspepsia in patients under 50-55 years without alarm symptoms 1, 2
• Gastric MALT lymphoma 1, 3
• Family history of gastric cancer 1
• Family history of peptic ulcer disease 1
• First-generation immigrants from high H. pylori prevalence countries (e.g., East Asian, Hispanic, African American populations) 1
• Long-term PPI therapy (>1 year) due to increased atrophic gastritis risk 2, 3
• Iron deficiency anemia (eradication improves hemoglobin and ferritin) 2
• Atrophic gastritis or intestinal metaplasia 3

When to Skip Testing and Go Directly to Endoscopy

• Age ≥50-55 years with new-onset dyspepsia (increased malignancy risk) 1, 3, 4
• Any age with alarm symptoms: bleeding, weight loss, dysphagia, palpable mass, anemia, malabsorption 1, 3, 4
• Known history of gastric ulcer (requires repeat endoscopy with biopsy until healed to rule out malignancy) 1

Which Test to Use

Non-Invasive Tests (First-Line for Young Patients Without Alarm Symptoms)

Urea Breath Test (UBT)

• Accuracy: Sensitivity 94.7-97%, Specificity 95-97.7% 3
• Best for: Initial diagnosis and confirmation of eradication 1, 2, 3
• Detects active infection only (not past exposure) 2, 3

Stool Antigen Test

• Accuracy: Sensitivity 93.2%, Specificity 93.2% 3, 4
• Must use laboratory-based monoclonal antibody tests (not rapid in-office tests, which have poor accuracy) 1, 2, 3
• Detects active infection only 2, 4

Serology (IgG Antibodies)

• Accuracy: Only 78% (68-82% range) 3
• Major limitation: Cannot distinguish active infection from past exposure; antibodies persist for years after eradication 2, 3
• Never use for confirmation of eradication 2, 3
• Only acceptable when: Recent antibiotic/PPI use makes other tests unreliable, or in bleeding ulcers, atrophic gastritis, or gastric malignancies where bacterial load may be low 3
• Avoid rapid in-office serological tests (sensitivity 63-97%, specificity 68-92%) 1, 3

Invasive Tests (During Endoscopy)

Rapid Urease Test

• Quick results during endoscopy 1, 3
• Affected by PPIs (can cause false negatives) 3

Histology

• Requires ≥2 biopsies from antrum and body 3
• Immunohistochemistry with H. pylori-specific antibodies is most accurate 1

Culture with Susceptibility Testing

• Essential after treatment failure to guide subsequent therapy 3
• Particularly valuable in regions with high clarithromycin resistance (>15-20%) 3

Critical Medication Washout Periods

Before Testing (To Avoid False Negatives)

• Stop PPIs for ≥2 weeks before UBT, stool antigen test, rapid urease test, histology, or culture 2, 3
  • PPIs suppress bacterial density by 10-40%, causing false negatives 3
  • H2-receptor antagonists (like famotidine) do NOT affect bacterial load and can be substituted if acid suppression is needed 2, 3
• Stop antibiotics for ≥4 weeks before testing 2, 3
• Stop bismuth products for ≥4 weeks before testing 2, 3

After Treatment (Confirmation of Eradication)

• Wait ≥4 weeks after completing eradication therapy before testing 2, 3, 4
• Use UBT or stool antigen test only (never serology) 2, 3

Treatment Approach

All positive H. pylori tests should be treated immediately to eliminate risks of peptic ulcer mortality and gastric cancer, regardless of symptom status. 2, 3

Young Patients (<50 years) Without Alarm Symptoms

• Treat immediately after positive test without requiring endoscopy ("test and treat" strategy) 2, 3
• This reduces unnecessary endoscopies by 62% while maintaining equivalent safety 3

Confirmation of Eradication

• Strongly recommended for: Complicated peptic ulcer disease, gastric ulcer, gastric MALT lymphoma 3
• May not be necessary for: Uncomplicated duodenal ulcer or functional dyspepsia when symptoms resolve 1

Common Pitfalls to Avoid

• Testing while on PPIs: Causes 10-40% false-negative rates 3. Always stop PPIs ≥2 weeks before testing 2, 3
• Using serology for post-treatment confirmation: Antibodies persist for years; this will give false positives 2, 3
• Testing too soon after treatment: Wait ≥4 weeks to avoid false results 2, 3
• Using rapid in-office tests: Poor accuracy (63-97% sensitivity); use laboratory-based tests only 1, 2, 3
• Failing to test family members: Person-to-person transmission occurs within families; test and treat household contacts of infected patients 1