<i>Helicobacter pylori</i>: tests

Helicobacter pylori: tests

• 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)
  Urea breath test - no antibiotics in past 4 weeks, no antisecretory drugs (e.g. PPI) in past 2 weeks
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  Importance: 78
• sensitivity 95-98%, specificity 97-98%
• may be used to check for H. pylori eradication
  Urea breath test is the only test recommended for H. pylori post-eradication therapy
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  Importance: 79

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

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

• provide information on antibiotic sensitivity
• sensitivity 70%, specificity 100%

• histological evaluation alone, no culture
• sensitivity 95-99%, specificity 95-99%

• sensitivity 90%, specificity 95%

Pathophysiology of Helicobacter pylori