Helicobacter

Urea breath test

• patients consume a drink containing carbon isotope 13 (13C) enriched urea
• 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%
• may be used to check for H. pylori eradication

Rapid urease test (e.g. CLO test)

• biopsy sample is mixed with urea and pH indicator
• colour change if H pylori urease activity
• sensitivity 90-95%, specificity 95-98%

Serum antibody

• remains positive after eradication
• sensitivity 85%, specificity 80%