What are the recommended tests and treatment for Helicobacter pylori (H. pylori) infection?

Recommended Tests and Treatment for Helicobacter pylori Infection

The urea breath test (UBT) and stool antigen test are the recommended non-invasive tests for diagnosing H. pylori infection, while triple therapy consisting of a proton pump inhibitor, clarithromycin, and amoxicillin for 10-14 days is the first-line treatment. 1

Diagnostic Testing for H. pylori

Non-invasive Testing (Preferred Approach)

Non-invasive tests are recommended as first-line for diagnosing H. pylori infection, especially in patients under 45-50 years without alarm symptoms.

1. Urea Breath Test (UBT)

   • Gold standard non-invasive test with sensitivity of 94-96% and specificity of 93-100% 2, 3
   • Available in two forms:
     • 13C-UBT: Uses non-radioactive isotope, preferred for children and pregnant women 4
     • 14C-UBT: Uses minimal radioactive isotope, faster results (10 minutes vs 40 minutes) 5
   • How it works: Patient ingests labeled urea, which is hydrolyzed by H. pylori urease, producing labeled CO2 that can be detected in breath

2. Stool Antigen Test

   • Comparable accuracy to UBT with sensitivity and specificity of 93.2% 1
   • Polyclonal antibody test widely used; monoclonal antibody tests under investigation
   • European Helicobacter Pylori Study Group recommends either UBT or stool testing for initial diagnosis 1

3. Serology (Anti-H. pylori IgG)

   • Less accurate (sensitivity 85%, specificity 79%) 1
   • Cannot distinguish between active infection and previous exposure
   • Not recommended as primary test unless high pretest probability exists (e.g., active duodenal ulcer)

Invasive Testing (Requires Endoscopy)

Reserved for patients with:

• Age >45-55 years
• Alarm symptoms (anemia, weight loss, dysphagia, palpable mass, melena)
• Failed eradication therapy requiring culture and antimicrobial sensitivity testing

1. Endoscopic Biopsy-Based Tests:
   • Histological examination (with immunohistochemistry being most accurate)
   • Rapid urease test
   • Culture
   • PCR analysis

Treatment of H. pylori Infection

First-Line Treatment

Triple Therapy:

• Omeprazole 20 mg twice daily
• Clarithromycin 500 mg twice daily
• Amoxicillin 1 g twice daily
• Duration: 10-14 days 6

This regimen has shown H. pylori eradication rates of 77-90% in clinical trials 6.

Alternative Treatment (If Clarithromycin Resistance Suspected)

Dual Therapy:

• Omeprazole 40 mg once daily
• Clarithromycin 500 mg three times daily
• Duration: 14 days
• Followed by omeprazole 20 mg once daily for another 14 days 6

Important Considerations

• Patients not eradicated of H. pylori following triple therapy will likely have clarithromycin-resistant H. pylori isolates
• Clarithromycin susceptibility testing should be performed when possible after treatment failure
• Patients with clarithromycin-resistant H. pylori should not be treated with regimens containing clarithromycin as the sole antimicrobial agent 6

Test and Treat Strategy

For young (<45-50 years) dyspeptic patients without alarm symptoms:

1. Test for H. pylori using non-invasive methods (UBT or stool antigen test)
2. If positive, treat with appropriate antibiotic regimen
3. If negative or symptoms persist after treatment, consider other diagnoses

This strategy has been shown to:

• Reduce the need for endoscopy by up to 62%
• Be cost-effective compared to prompt endoscopy
• Provide similar symptom relief and patient satisfaction 1

Common Pitfalls to Avoid

1. False-negative test results can occur if patient has recently taken:

   • Antibiotics (within 4 weeks)
   • Bismuth compounds
   • Proton pump inhibitors (PPIs)

2. Serology limitations:

   • Remains positive after successful eradication
   • Should not be used to confirm eradication

3. Treatment failure factors:

   • Poor compliance
   • Antibiotic resistance (particularly clarithromycin)
   • Inadequate acid suppression

Always confirm eradication after treatment using UBT or stool antigen test, performed at least 4 weeks after completion of therapy and after stopping PPIs for at least 2 weeks.