Helicobacter pylori infection

H. pylori - The Stomach Squatter

• Gram-negative, spiral-shaped bacterium that colonizes the gastric mucosa.
• Produces urease, which hydrolyzes urea into $NH_3$ and $CO_2$ to neutralize local acid.
• Transmission: Fecal-oral or oral-oral routes.

Clinical Associations:

• Chronic gastritis & Peptic Ulcer Disease (PUD), especially duodenal ulcers.
• Gastric Adenocarcinoma & MALT Lymphoma.

Diagnosis & Management:

• Tests: Urea breath test, stool antigen, or endoscopy with biopsy.
• Treatment:
  • 📌 CAP regimen: Clarithromycin + Amoxicillin + PPI.
  • Quadruple Therapy for resistance: Bismuth + Metronidazole + Tetracycline + PPI.

⭐ H. pylori is the only bacterium classified as a Class I carcinogen, directly linked to gastric cancer.

Clinical Features - Gut Feelings

• Majority Asymptomatic: Most individuals are carriers without symptoms.
• Chronic Gastritis: The most common clinical outcome.
  • Epigastric pain (burning, gnawing), often worse at night or with an empty stomach.
  • Nausea, bloating, and early satiety.
• Peptic Ulcer Disease (PUD):
  • Duodenal Ulcer: Pain classically improves with meals.
  • Gastric Ulcer: Pain classically worsens with meals.
• Alarm Features: Unintentional weight loss, persistent vomiting, dysphagia, melena/hematemesis, or iron deficiency anemia (IDA).

⭐ H. pylori infection is the strongest known risk factor for gastric MALT lymphoma; successful eradication therapy leads to lymphoma regression in ~75% of cases.

Diagnosis - The Great Detective

• Initial Approach: Choice of test depends on indication for endoscopy.

• Non-Invasive Tests:
  • Urea Breath Test (UBT) & Stool Antigen: High sensitivity/specificity for active infection. Used for initial diagnosis and to confirm eradication.
  • Serology (IgG): Shows exposure, not active disease. 📌 Stays positive after eradication.

⭐ Test-Modifying Meds: Stop PPIs for 2 weeks and antibiotics/bismuth for 4 weeks before UBT or stool antigen testing to avoid false negatives.

Treatment - Eviction Notice

• Goal: Eradicate H. pylori to heal peptic ulcers, treat MALT lymphoma, and reduce gastric cancer risk.

• First-Line Therapy (10-14 days):

  • Bismuth Quadruple: PPI + Bismuth + Metronidazole + Tetracycline.
    • Preferred if clarithromycin resistance is high or patient had macrolide exposure.
    • 📌 Please Make Tummy Better (PPI, Metro, Tetra, Bismuth).
  • Clarithromycin Triple: PPI + Clarithromycin + Amoxicillin.
    • Use only if local clarithromycin resistance is <15%.
    • Use Metronidazole for Amoxicillin if penicillin allergy.

• Salvage Therapy: If first-line fails, use an alternative regimen (e.g., Levofloxacin-based).

⭐ Confirm eradication with urea breath test or fecal antigen test >4 weeks after ending antibiotics and >2 weeks after stopping PPIs to prevent false negatives.

• H. pylori is a gram-negative, spiral-shaped bacterium strongly associated with peptic ulcer disease (PUD), especially duodenal ulcers.
• It is a major risk factor for gastric adenocarcinoma and MALT lymphoma.
• Urea breath test and stool antigen testing are the preferred non-invasive diagnostic methods.
• Standard treatment is triple therapy: a Proton Pump Inhibitor (PPI), clarithromycin, and amoxicillin.
• Always confirm eradication with a urea breath or stool antigen test >4 weeks after completing therapy.