What is the evaluation and treatment approach for a patient with suspected Helicobacter pylori (HP) infection, particularly those with symptoms of gastrointestinal disease, such as abdominal pain, bloating, or dyspepsia, and a history of peptic ulcer disease or gastric cancer?

Evaluation of Helicobacter pylori Infection

Who Should Be Tested for H. pylori

All patients with current or past peptic ulcer disease, uninvestigated dyspepsia, gastric MALT lymphoma, family history of gastric cancer or peptic ulcer disease, and those planning long-term NSAID use should be tested for H. pylori infection. 1

High-Priority Testing Indications (100% Agreement, High Evidence):

• Active or past gastric or duodenal ulcers 1
• Uninvestigated dyspepsia 1
• Suspected H. pylori infection (e.g., active duodenal ulcer) 1

Additional Testing Indications:

• Gastric MALT lymphoma (100% agreement, moderate evidence) 1
• Family history of gastric cancer (100% agreement, moderate evidence) 1
• Family history of peptic ulcer disease (91% agreement, moderate evidence) 1
• First-generation immigrants from high-prevalence areas (82% agreement, high evidence) 1
• High-risk ethnic groups in the United States (Latino, African American, East Asian populations have 2.6-3.2-fold higher prevalence) 1
• Family members living in the same household as H. pylori-positive patients (91% agreement, moderate evidence) 1

Diagnostic Testing Methods

Non-Invasive Tests (Preferred for Initial Diagnosis):

The urea breath test (13C-UBT) is the gold standard non-invasive test for diagnosing active H. pylori infection, with the highest diagnostic accuracy. 1, 2

• 13C-Urea Breath Test: Sensitivity 94% at 90% specificity; diagnostic odds ratio 153 3
• 14C-Urea Breath Test: Sensitivity 92% at 90% specificity; diagnostic odds ratio 105 3
• Stool Antigen Test: Sensitivity 83% at 90% specificity; diagnostic odds ratio 45.1 (use validated monoclonal antibody tests) 1, 2, 3

Tests to Avoid:

• Serology (IgG antibodies): Lower accuracy with sensitivity 84% at 90% specificity; diagnostic odds ratio 47.4 1, 3
• Serology is no longer recommended or reimbursed by Medicare 1
• IgA and IgM tests are not FDA-approved and should not be used 1
• Never use serology to confirm eradication as antibodies persist long after successful treatment 4

Invasive Tests (When Endoscopy Is Performed):

When endoscopy is indicated, obtain biopsies from both antrum and body for histology with immunohistochemical staining, plus one biopsy for rapid urease test. 1

• Histology with immunohistochemistry: Most accurate method for detecting H. pylori in biopsy specimens 1
• Rapid urease test: Quick, inexpensive test performed during endoscopy 1, 5
• Culture: Allows antimicrobial susceptibility testing; essential after two failed eradication attempts 1, 4

Critical Testing Precautions:

Stop proton pump inhibitors (PPIs) for at least 2 weeks and antibiotics/bismuth for at least 4 weeks before testing to avoid false-negative results. 1, 2, 4

• PPIs can cause false-negative results on all tests except serology 1, 2
• In patients on PPIs, obtain biopsies from both corpus and antrum, as H. pylori may migrate proximally 1

When to Perform Endoscopy vs. Non-Invasive Testing

Proceed Directly to Endoscopy:

• Age ≥45 years with new dyspeptic symptoms (gastric cancer risk threshold) 1
• Any age with alarm symptoms: anemia, weight loss, dysphagia, palpable mass, evidence of GI bleeding 1, 2
• Known history of gastric ulcer (requires repeat endoscopy with biopsy until healed to exclude malignancy) 1
• Persistent symptoms despite H. pylori eradication and empirical PPI therapy 2

Use Non-Invasive "Test and Treat" Approach:

• Age <45 years (or <55 years per some guidelines) without alarm symptoms 1, 2
• This approach is equally effective and more cost-efficient than prompt endoscopy 2

Confirmation of Eradication After Treatment

Test for eradication success at least 4 weeks after completing therapy using urea breath test or validated monoclonal stool antigen test, with PPIs discontinued for at least 2 weeks before testing. 1, 2, 4

When Confirmation Testing Is Mandatory:

• Complicated peptic ulcer disease 1
• Gastric ulcer (requires endoscopy to exclude malignancy) 1
• Low-grade gastric MALT lymphoma 1
• History of peptic ulcer bleeding 1, 6
• Poor treatment compliance 1

When Confirmation May Not Be Necessary:

• Uncomplicated duodenal ulcer with complete symptom resolution 1
• Non-ulcer dyspepsia with symptom resolution 1

Method for Confirmation:

• Preferred: 13C-urea breath test (gold standard) 1, 2
• Alternative: Validated monoclonal stool antigen test 2, 4
• Never use serology for confirmation (antibodies persist for months after eradication) 1, 4

Common Pitfalls to Avoid

• Do not test patients on PPIs without stopping them first (causes false negatives on all tests except serology) 1, 2
• Do not use rapid office-based serological tests (sensitivities 63-97%, specificities 68-92% in validation studies) 1
• Do not assume negative biopsy urease test in bleeding peptic ulcer (perform urea breath test to rule out false negative) 7
• Do not test asymptomatic populations for screening purposes (not recommended outside high gastric cancer prevalence areas) 6
• Do not delay testing family members of H. pylori-positive patients (person-to-person transmission occurs within families) 1