Helicobacter pylori
🎯 Treatment of H. pylori aims to eradicate infection, reduce peptic ulcer disease and bleeding risk, and prevent recurrence, gastric cancer, and MALT lymphoma.
📖 About
- Discovered by Barry Marshall & Robin Warren in 1982 🧪.
- Most common cause of peptic ulceration, though many carriers are asymptomatic.
- Present in ~95% of duodenal ulcers and 70–80% of gastric ulcers.
- NSAIDs + H. pylori = 🔥 high ulcer risk.
- Associated with acute/chronic gastritis, gastric adenocarcinoma, and MALT lymphoma (regresses after eradication in many cases).
🔬 Electron Microscopy
🌍 Source
- Spread mainly person-to-person → oral–oral or faeco–oral.
- More common in older adults and in lower socioeconomic groups.
- Humans are the main reservoir (occasionally found in cats 🐈).
⚙️ Characteristics
- Spiral-shaped, Gram-negative, highly motile bacillus.
- Microaerophilic with 4–6 unipolar flagella.
- Urease production → breaks down urea to ammonia → neutralises gastric acid locally.
- Lives beneath gastric mucous layer and adheres to epithelial cells.
🧨 Virulence
- Causes neutrophilic gastritis.
- CagA gene linked to severe disease and higher gastric cancer risk.
- Produces urease and VacA toxin → epithelial injury.
🩺 Pathogenicity
- Antral gastritis → achlorhydria + ↑ gastrin + ↑ acid secretion.
- Chronic duodenal ulcers (95% cases) & gastric ulcers (70–80%).
- Gastric cancer: adenocarcinoma (80% linked to H. pylori).
- MALT lymphoma: may regress after eradication.
🧪 Investigations
- 🩸 Serology: Detects IgG → cannot distinguish past from current infection.
- 💨 Urea Breath Test (13C/14C): Most accurate non-invasive test.
- 💩 Stool Antigen Test (SAT): Confirms active infection.
- 🔬 Histology + biopsy urease (CLO test): High sensitivity/specificity.
- 🧫 Culture: Gold standard but slow (used for resistance testing).
💊 Management (UK)
- First-line (Triple Therapy): for 1 week
- Clarithromycin 500 mg BD
- Amoxicillin 1 g BD (or Metronidazole if penicillin-allergic)
- PPI (Omeprazole 20 mg BD or equivalent)
- Second-line (if failure or resistance):
- Metronidazole 400 mg TDS
- Amoxicillin 1 g BD
- PPI BD
- Treatment is indicated for:
- Peptic ulcer disease (gastric & duodenal)
- MALT lymphoma
- Post-bleed ulcers & atrophic gastritis
- Routine screening for asymptomatic carriers is not recommended in low-risk groups.
📚 References
