What are the recommended initial tests for H. pylori (Helicobacter pylori) detection in patients with functional dyspepsia?

H. Pylori Testing Options for Functional Dyspepsia

For patients with functional dyspepsia requiring H. pylori testing, use either the 13C-urea breath test or stool antigen test as first-line non-invasive diagnostic methods, as these have superior accuracy compared to serological testing. 1, 2

Recommended Non-Invasive Tests (in order of preference)

First-Line Options

• 13C-urea breath test: This is one of the two optimal non-invasive tests with high sensitivity and specificity 1, 2
• Stool antigen test (monoclonal): Equally accurate to breath testing and appropriate for initial diagnosis 1, 2
  • The Amplified IDEIA Hp StAR enzyme immunoassay test demonstrates 90% sensitivity and 89% specificity, making it the most accurate stool test option 3

Tests to Avoid

• Serological testing (IgG/IgM antibodies): Not recommended as a primary diagnostic method due to lower specificity (less than 90% in most cases) and inability to distinguish active from past infection 1, 2
• Whole blood tests: Most currently available versions have inadequate sensitivity and specificity 1

Clinical Context for Testing

When to Test

• All patients with dyspepsia who are under age 55 (or under the local age cutoff for gastric cancer risk) without alarm features should undergo non-invasive H. pylori testing as part of a "test and treat" strategy 1
• This approach is particularly cost-effective in populations with H. pylori prevalence ≥10% 1, 4

Test Selection Considerations

• In primary care settings: The test must have sensitivity and specificity of at least 90% to minimize false positives in low-prevalence populations and false negatives in high-prevalence areas 1
• Negative predictive value: This is particularly important because patients with negative results typically receive reassurance without retesting 1

Post-Treatment Confirmation Testing

When Confirmation is Needed

• Routine confirmation is NOT recommended for most patients after eradication therapy 1, 2
• Confirm eradication only in: Patients at increased risk of gastric cancer (age >40 from high-risk areas, family history of gastro-oesophageal cancer) 1, 2

Methods for Confirmation

• Use either urea breath test or stool antigen test—never serology, as antibodies remain positive long after successful eradication 2, 5
• Perform confirmation testing at least 4 weeks after completing eradication therapy 5

Common Pitfalls to Avoid

• Do not use serological testing as your primary diagnostic tool—it cannot distinguish active infection from past exposure and has lower cost-effectiveness 1, 2
• Timing matters: Ensure patients are off proton pump inhibitors for at least 2 weeks and antibiotics for at least 4 weeks before testing, as these can cause false-negative results 6
• In-office rapid immunochromatographic tests (like RAPID Hp StAR and ImmunoCard STAT! HpSA) show variable accuracy with sensitivities ranging from 69-92% and may have observer-dependent interpretation issues 3

Algorithm for Test Selection

1. First choice: 13C-urea breath test OR monoclonal stool antigen test (if available and affordable) 1, 2
2. If neither available: Use a locally validated serological test with documented sensitivity and specificity ≥90% 1
3. For confirmation post-treatment (only in high-risk patients): Breath test or stool antigen test, never serology 1, 2