Helicobacter Pylori Infection
NICE Clinical guideline [CG184] Gastro-oesophageal reflux disease and dyspepsia in adults: investigation and management. Last updated: Oct 2019.
BNF Treatment summaries. Helicobacter pylori infection.
UK Health Security Agency Guidance Helicobacter pylori in dyspepsia: test and treat. Last updated: May 2025.
Background information added accordingly. Minor changes and restructuring to the diagnosis and management sections, based on UK Health Security Agency Guidance.
Date: 23/11/25
Background Information
Causative Agent
H. pylori is a gram -ve spiral-shaped bacterium with multiple flagella
Pathophysiology
H. pylori infection is characterised by persistent colonisation of the gastric mucosa:
- H. pylori survives gastric acidity by producing urease, which hydrolyses urea to ammonia to neutralise the gastric acid locally
- H. pylori causes chronic inflammation by producing virulence factors (CagA and VacA)
- Inflammation results in
- ↓ Mucus production
- ↓ Bicarbonate secretion
- Damage to tight junction
Clinical Features
H. pylori infection is very common and is often asymptomatic: [Ref]
- ~40% people in the UK has H. pylori infection
- Only ~1 in 10 people will experience symptoms or complications
Clinical manifestation of H. pylori infection: [Ref]
- Chronic gastritis (which may present as dyspepsia)
- Peptic ulcer disease (H. pylori is a leading contributing factor)
Although rare, H. pylori is also a well-established risk factor for: [Ref]
- Gastric MALT lymphoma
- Gastric adenocarcinoma
Diagnosis
Investigation and Diagnosis
Offer a non-invasive test:
| Test | Description | Interpretation |
|---|---|---|
| Urea 13C breath test | Preferred test (most accurate test) | ↑ ¹³C in exhaled breath = active H. pylori infection |
| Stool antigen test | Preferred test | Positive = current active infection |
| Serology (IgG) | Low accuracy (not recommended for most patients) (+ve tests should be confirmed by a second test | Positive = past or current exposure (not reliable for active infection) |
Urea 13C breath test and stool antigen test should be delayed if the patient:
- Takes PPI → delay until after 2 weeks of not taking it
- Take antibiotics → delay until after 4 weeks of not taking them
This is because PPIs and antibiotics will suppress bacteria and can lead to false -ve
Invasive testing for H. pylori can be done during endoscopy using rapid urease test (CLO test).
However, it is not recommended as 1st line for H. pylori testing. They are only performed if an endoscopy is necessary for another indication (e.g. ulcer investigation, suspected malignancy)
Management
Offer H. pylori eradication to those with +ve H. pylori testing (urea breath test or stool antigen test)
- Standard regimen: triple-therapy regimen (1 PPI and 2 antibiotics)
Early-stage of gastric MALT lymphoma can be effectively treated with H. pylori eradication
Choice of H. Pylori Eradication Therapy
Disclaimer: only 1st and 2nd line recommended regimens are included for educational purposes.
Longer duration (>7 days) or 3rd line eradication should only be offered under specialist advice.
Some common PPI medications: lansoprazole 30mg BD, omeprazole 20-40 mg BD
| Patients with NO penicillin allergy | Patients WITH penicillin allergy | |
|---|---|---|
| 1st line | 7 days triple therapy of:
|
7 days triple therapy of:
|
| 2nd line (ongoing symptoms after 1st line) | 7 days triple therapy of:
|
7-days quadruple therapy of:
|
If 2nd line therapy is not effective → seek specialist advice
Re-Testing
Do not routinely offer re-testing after H. pylori eradication therapy
Indications
Consider re-testing if:
- Poor compliance to eradication therapy
- High local resistance rates
- Severe / persistent / recurrent symptoms
- Patients with associated peptic ulcer / MALT lymphoma / after resection of early gastric carcinoma
- Initial test was performed within 2 weeks of PPI or 4 weeks of antibiotic
- Aspirin or NSAID is indicated, esp. if there is a history of peptic ulcer disease
- Family history of gastric malignancy
- Person requests re-testing
Testing Details
Retesting should be performed at least 4 weeks (ideally 8 weeks) after initial eradication therapy
Test of choice:
- 1st line: urea 13 C breath test
- 2nd line: stool antigen test
- Do NOT use serology for re-testing
Before performing a urea 13 C breath test or stool antigen test make sure that the patient has not taken a PPI in the past 2 weeks, or antibiotics in the past 4 weeks.
If patients require treatment in between those times → use histamine2-receptor antagonists before testing (instead of PPI)
References