When to suspect Helicobacter (H.) pylori infection in a patient with abdominal pain, bloating, or nausea, particularly those with a history of gastrointestinal disease, peptic ulcer disease, or gastritis?

When to Suspect H. pylori Infection

Suspect H. pylori infection in any patient presenting with dyspepsia, particularly those under 50-55 years without alarm symptoms, as well as in patients with peptic ulcer disease, unexplained iron-deficiency anemia, or a family history of gastric cancer. 1, 2

Primary Clinical Scenarios Requiring H. pylori Testing

Gastrointestinal Symptoms

• Dyspepsia in younger patients (<50-55 years): Test all patients with uninvestigated dyspepsia who lack alarm symptoms using the "test and treat" strategy with non-invasive testing (urea breath test or stool antigen test). 1, 2
• Peptic ulcer disease: All patients with active or documented history of gastric or duodenal ulcers should be tested, as H. pylori is present in 66% of duodenal ulcers and 55% of gastric ulcers. 3, 1, 4
• Recurrent or persistent upper abdominal pain: Particularly when associated with bloating or nausea, especially if symptoms are chronic or recurrent despite symptomatic treatment. 3

High-Risk Populations and Conditions

• Family history of gastric cancer or peptic ulcer disease: First-degree relatives of patients with these conditions warrant testing due to shared environmental exposure and genetic susceptibility. 3, 2
• Gastric MALT lymphoma: All patients with this diagnosis require H. pylori testing, as the infection is causally related. 3, 1
• Atrophic gastritis or intestinal metaplasia: These premalignant conditions are strongly associated with H. pylori and increase gastric cancer risk. 3, 1
• Long-term PPI therapy (>1 year): Testing is indicated due to increased risk of atrophic gastritis development. 1

Hematologic and Nutritional Disorders

• Unexplained iron-deficiency anemia: H. pylori can cause chronic blood loss and impaired iron absorption. 2
• Idiopathic thrombocytopenic purpura (ITP): Testing is recommended as eradication may improve platelet counts. 2
• Vitamin B12 deficiency: Particularly when associated with atrophic gastritis. 2

Geographic and Demographic Risk Factors

• First-generation immigrants from high-prevalence countries: Individuals from Asia, Latin America, Eastern Europe, and Africa have substantially higher infection rates. 2
• Patients from high gastric cancer risk regions: Those with ancestry from Japan, China, Korea, or other areas with gastric cancer incidence ≥20 per 100,000 person-years. 3

Alarm Symptoms Requiring Immediate Endoscopy (Not Just Testing)

Proceed directly to endoscopy rather than non-invasive testing in patients presenting with any of the following, regardless of age: 3, 1

• Gastrointestinal bleeding or anemia
• Unintentional weight loss
• Dysphagia (difficulty swallowing)
• Persistent vomiting
• Palpable abdominal mass
• Age >50-55 years with new-onset dyspepsia
• Family history of gastric cancer in patients >40 years

Clinical Context for Testing Approach

When to Use Non-Invasive Testing

Use urea breath test or laboratory-based monoclonal stool antigen test as first-line in: 1, 2

• Patients <50-55 years with dyspepsia and no alarm symptoms
• Asymptomatic relatives of peptic ulcer patients
• Screening in high-risk populations
• Post-treatment confirmation of eradication (≥4 weeks after therapy completion)

When to Proceed Directly to Endoscopy

Endoscopy with biopsy-based testing is indicated for: 3, 1

• Patients ≥50-55 years with new-onset dyspepsia
• Any patient with alarm symptoms
• Patients requiring evaluation for gastric ulcer healing or malignancy exclusion
• Treatment failures requiring culture and antibiotic susceptibility testing
• Suspected gastric MALT lymphoma or atrophic gastritis

Critical Testing Considerations and Pitfalls

Medication Washout Requirements

To avoid false-negative results, ensure proper medication cessation before testing: 3, 1

• Proton pump inhibitors: Stop ≥2 weeks before testing (causes 10-40% false-negative rates)
• Antibiotics and bismuth: Stop ≥4 weeks before testing
• H2-receptor antagonists: Do not affect bacterial load and can substitute for PPIs when acid suppression is needed

Special Circumstances Where Serology May Be Considered

While serology is generally not recommended due to inability to distinguish active from past infection (78% accuracy), it may be useful when: 1

• Recent antibiotic or PPI use precludes other testing and clinical suspicion is high
• Gastric atrophy, malignancy, or active ulcer bleeding may cause false-negative non-invasive tests
• Large epidemiologic surveys in high-prevalence populations

Never use serology for post-treatment confirmation of eradication, as antibodies remain elevated after successful treatment. 1, 2

Age-Related Considerations

The natural history of H. pylori-related gastric cancer shows exponential risk increase with age, making early detection and treatment particularly important in younger patients to halt disease progression. 3 However, older patients (≥50-55 years) with new symptoms require endoscopy due to increased malignancy risk rather than non-invasive testing alone. 1, 2