Initial assessment
The approach to Helicobacter pylori should begin by assessing the clinical indication for testing. This bacterium is associated with peptic ulcer disease, chronic active gastritis, gastric MALT lymphoma and distal gastric carcinoma, and may also contribute to dyspepsia and unexplained iron deficiency anaemia. The presence of an indication determines whether testing should be performed and which diagnostic strategy is most appropriate.
Indications for testing
Patients should be tested if they have persistent dyspeptic symptoms without previous investigation, active peptic ulcer disease or a previous history of ulcer without documented eradication, low-grade gastric MALT lymphoma, or if they have undergone endoscopic resection of early gastric lesions. There are also indications with consistent clinical benefit, such as idiopathic iron deficiency anaemia, immune thrombocytopenic purpura and patients receiving prolonged treatment with acetylsalicylic acid or NSAIDs when ulcerogenic risk is present.
Alarm features and need for endoscopy
Before choosing non-invasive methods, alarm features should be identified: gastrointestinal bleeding, unintentional weight loss, persistent vomiting, dysphagia, odynophagia, iron deficiency anaemia or family history of gastric carcinoma. In these situations, upper gastrointestinal endoscopy with biopsy is indicated for morphological assessment and detection of H. pylori.
Diagnostic methods
In the absence of alarm features and in patients younger than 60 years, non-invasive methods such as the urea breath test or stool antigen test may be used, both with high sensitivity and specificity. To reduce false negatives, PPIs should be stopped for at least 2 weeks and recent antibiotic use should be excluded. Serology is not suitable for confirming eradication.
Eradication therapy — first line
Once infection is confirmed, eradication therapy should be started. The preferred regimen is bismuth quadruple therapy for 14 days (PPI + bismuth + tetracycline + metronidazole), due to increasing clarithromycin resistance. When bismuth is unavailable and there is no penicillin allergy, concomitant therapy with a PPI, amoxicillin, clarithromycin and metronidazole for 14 days may be used.
Special considerations — penicillin allergy
In true penicillin allergy, the regimen of choice is bismuth quadruple therapy, as it does not include amoxicillin. If bismuth is unavailable or treatment failure occurs, empirical options become limited, and referral to Gastroenterology for culture and susceptibility testing should be considered.
Confirmation of eradication
Eradication should be confirmed in all treated patients using a urea breath test or stool antigen test. Confirmation should not be performed before 4 weeks after antibiotic therapy and after 2 weeks without PPIs, ideally 4 weeks without bismuth. Serology should not be used for post-treatment confirmation.
Rescue therapy
In the event of first-line treatment failure, previously administered antibiotics should not be reused. After bismuth-containing regimens, levofloxacin + amoxicillin + PPI for 14 days is commonly used as second-line therapy, provided there has been no previous exposure to fluoroquinolones. After second-line failure, rifabutin + amoxicillin + PPI may be used as third-line therapy or, preferably, culture with susceptibility testing should be performed.
Referral to Gastroenterology
Referral should be considered in cases of multiple treatment failures, penicillin allergy with limited empirical options, need for culture/antibiogram or structural gastric pathology requiring endoscopic assessment.
Additional considerations
Isolated gastro-oesophageal reflux is not an indication for H. pylori testing, but if the patient is tested and the result is positive, eradication should be proposed. The use of probiotics during therapy may reduce gastrointestinal adverse effects and improve adherence, although the impact on eradication rates is variable.
