Helicobacter Pylori Infection

A 45-year-old man presents with chronic epigastric pain for the past 3 months. The pain is burning in nature, occurs 2–3 hours after meals, and often awakens him at night. He reports that the pain is relieved by eating and antacids. He also complains of bloating and intermittent nausea. He has been taking NSAIDs intermittently for joint pain. There is no history of weight loss, dysphagia, vomiting, or gastrointestinal bleeding. On examination, he has mild epigastric tenderness without guarding or rigidity. Laboratory studies show mild microcytic anemia. A urea breath test is positive. Diagnosis?

Diagnosis is Helicobacter pylori–associated duodenal ulcer disease.

1. Definition

Helicobacter pylori is a spiral-shaped, Gram-negative, urease-producing bacterium that colonizes the gastric mucosa and causes chronic gastritis, peptic ulcer disease, and increases the risk of gastric adenocarcinoma and MALT lymphoma.

2. Epidemiology

1. Very common worldwide infection
2. Approximately 50 percent of the global population is infected
3. Prevalence in North America is about 30 to 40 percent
4. Typically acquired in childhood
5. Infection persists lifelong unless treated
6. Higher prevalence with overcrowding, poor sanitation, low socioeconomic status, and endemic regions

3. Etiology and Transmission

1. Humans are the primary reservoir
2. Transmission via oral-oral or fecal-oral routes
3. Infection usually acquired early in life
4. Risk increases with poor hygiene and crowded living conditions

4. Pathophysiology

1. Produces urease → ammonia → neutralizes gastric acid locally
2. Causes chronic gastric mucosal inflammation
3. Antral-predominant gastritis → increased acid → duodenal ulcer
4. Corpus-predominant gastritis → reduced acid → gastric ulcer and cancer risk
5. Chronic inflammation → atrophic gastritis → intestinal metaplasia → dysplasia → gastric adenocarcinoma
6. Associated with MALT lymphoma (may regress after eradication)
7. Virulence factors:
   o CagA → increased inflammation and cancer risk
   o VacA → mucosal injury

5. Clinical Features

5.1 Common Presentation

1. Often asymptomatic
2. Dyspepsia
3. Epigastric pain or burning
4. Bloating
5. Nausea
6. Early satiety
7. Belching

5.2 Ulcer-Type Symptoms

1. Duodenal ulcer pain relieved by food or antacids
2. Gastric ulcer pain worsened by food
3. Nocturnal pain

5.3 Alarm Features

1. GI bleeding (hematemesis, melena, hematochezia)
2. Unintentional weight loss
3. Iron deficiency anemia
4. Dysphagia or odynophagia
5. Persistent vomiting
6. Palpable abdominal mass or lymphadenopathy
7. Jaundice

6. Complications

1. Peptic ulcer disease (duodenal > gastric)
2. Upper GI bleeding (most common complication)
3. Perforation
4. Gastric outlet obstruction
5. Gastric adenocarcinoma
6. MALT lymphoma
7. Iron deficiency anemia
8. Immune thrombocytopenic purpura

7. When to Test for H. pylori

1. Dyspepsia <60 years without alarm features (test-and-treat)
2. Dyspepsia with alarm features → endoscopy with biopsy
3. Current or prior peptic ulcer disease
4. Unexplained iron deficiency anemia
5. Immune thrombocytopenic purpura
6. Adult household contacts of infected individuals
7. High-risk gastric conditions (atrophy, intestinal metaplasia, dysplasia, autoimmune gastritis)
8. Family history of gastric cancer
9. High-prevalence regions or high-risk populations
10. MALT lymphoma
11. Chronic NSAID use or before long-term aspirin therapy

8. Diagnosis

8.1 Noninvasive Tests

1. Urea breath test (preferred for active infection)
2. Stool antigen test (diagnosis and test-of-cure)
3. Serology (IgG)
   o Cannot distinguish active vs past infection

8.2 Invasive Tests (Endoscopy with Biopsy)

1. Rapid urease test
2. Histology
3. Culture (antibiotic susceptibility)
4. PCR (specialized use)

8.3 Medication Hold Before Testing

1. Stop PPIs or PCABs ≥2 weeks before testing
2. Stop antibiotics and bismuth ≥4 weeks before testing
3. Prevents false-negative results

9. Treatment

9.1 Principle

1. All patients with confirmed H. pylori infection should be treated

9.2 First-Line Therapy (Preferred)

Optimized Bismuth Quadruple Therapy (14 days)

1. PPI twice daily
2. Bismuth four times daily
3. Tetracycline 500 mg four times daily
4. Metronidazole 500 mg three or four times daily

9.3 Alternative Regimens

1. Rifabutin-based triple therapy
2. Vonoprazan + amoxicillin dual therapy (PCAB-based)
3. Vonoprazan + amoxicillin + clarithromycin
   o Only if clarithromycin susceptibility confirmed

9.4 Important Treatment Considerations

1. Avoid empiric clarithromycin-based triple therapy
2. Clarithromycin and levofloxacin resistance ↑ → reduced efficacy
3. Eradication rates drop markedly in resistant strains
4. Doxycycline is NOT a substitute for tetracycline in BQT

10. Test of Cure

1. Required in all patients
2. Perform ≥4 weeks after antibiotics
3. Stop PPIs/PCABs ≥2 weeks before testing
4. Use:
   o Urea breath test
   o Stool antigen test
   o Biopsy-based testing

11. Resistance Considerations

1. Clarithromycin resistance increasing globally
2. Levofloxacin resistance increasing
3. Amoxicillin resistance rare
4. Susceptibility-guided therapy preferred

12. Endoscopy Indications

1. Dyspepsia with alarm features
2. Persistent dyspepsia in older or high-risk patients
3. Failed empiric therapy
4. Suspected complications (bleeding, obstruction, malignancy)

13. Adjunct Measures

1. Discontinue NSAIDs when possible
2. Avoid smoking
3. Limit alcohol if symptomatic
4. No specific dietary restriction required
5. Evaluate penicillin allergy if limiting therapy

14. Key Clinical Insight

Dyspepsia/PUD/IDA/ITP or gastric cancer risk + positive H. pylori testing = H. pylori infection → treat with 14-day bismuth quadruple therapy → confirm eradication (urea breath test or stool antigen ≥4 weeks post-treatment, off PPI ≥2 weeks)

15. Exam Level Pearls

1. Helicobacter pylori is a major cause of peptic ulcer disease, especially duodenal ulcers
2. It is a World Health Organization class I carcinogen
3. Urea breath test and stool antigen test detect active infection
4. Serology cannot distinguish active from prior infection
5. Stop proton pump inhibitors for 2 weeks and antibiotics or bismuth for 4 weeks before testing
6. Bismuth quadruple therapy is the preferred first-line treatment
7. Avoid empiric clarithromycin triple therapy
8. Always confirm eradication after treatment
9. NSAID use plus Helicobacter pylori increases ulcer risk