Table V.

Diagnostic methods used in the diagnosis of H. pylori infection

Test name		Sensitivity	Specificity	Comments
Invasive tests:
	Urease test (CLO – test) Recommended	90%	95%	Cheap and quick, simple. False-negative result e.g. due to bleeding, post PPIs and antibiotics. PPIs should be discontinued 14 days before the test, and antibiotics and bismuth should be discontinued for 4 weeks.
	Histological examination	95%	98%	An expensive and time-consuming study. Assesses mucosal lesions. 14 days before the test, do not administer PPIs.
	Microbiological examination (bacterial culture)	40–70%	100%	Assesses the sensitivity of H. pylori to antibiotics. An expensive and time-consuming study. Difficult culture conditions. 14 days before the test, discontinue PPIs.
Non-invasive tests:
	H. pylori antigens in faeces Recommended	94%	97%	Cheap, simple and readily available. Confirms current infection and assesses the effectiveness of eradication. 14 days before the test, do not administer PPIs, and discontinue antibiotics and bismuth for 4 weeks.
	Breath test (using 13C or 14C-urea)	88–95%	95–100%	Confirms current infection and assesses the effectiveness of eradication. Difficult access. 14 days before the test, do not administer PPIs, and discontinue antibiotics and bismuth for 4 weeks.
	Serology (IgG or IgG + IgA)	85%	79%	Cheap, fast and useful for screening. Unsuitable for confirmation of current infection and eradication.