Presentation
Abdominal pain (usually epigastric, burning in nature)
Nausea
Laboratory investigations
Urea breath test
Patients consume a drink containing carbon isotope 13 (13C) enriched urea. The urea is broken down by H. pylori urease
after 30 mins patient exhale into a glass tube
mass spectrometry analysis calculates the amount of 13C CO2
should not be performed within 4 weeks of treatment with an antibacterial or within 2 weeks of an antisecretory drug (e.g. a proton pump inhibitor)
sensitivity 95-98%, specificity 97-98%
Serology
Will remain positive, even after eradication therapy
Sensitivity 85%, specificity 80%
Stool antigen test
sensitivity 90%, specificity 95%
Special investigations
OGD
Appearances of gastritis may be seen, eg gastric antral erythema
Rapid urease test (e.g. CLO test)
Biopsy sample (taken during OGD is mixed with urea and pH indicator
colour change if H pylori urease activity
Sensitivity 90-95%, specificity 95-98%
Gastric biopsy
Sensitivity 95-99%, specificity 95-99%
H. pylori may be visible in the superficial mucus
Neutrophils in lamina propria
Subepithelial plasma cells
Culture of gastric biopsy
provide information on antibiotic sensitivity
sensitivity 70%, specificity 100%
