Diagnosis of Helicobacter pylori: Invasive and non invasive tests.

Helicobacter pylori infection can be diagnosed by invasive techniques requiring endoscopy and biopsy
(e.g. histological examination, culture and rapid urease test) and by non-invasive techniques, such as
serology, the urea breath test, urine/blood or detection of H. pylori antigen in stool specimen. Some
non-invasive tests, such as the urea breath test and the stool antigen test, detect active infection:
these are called ‘active tests’. Non-invasive tests (e.g. serology, urine, near-patient tests) are markers
of exposure to H. pylori but do not indicate if active infection is ongoing; these are ‘passive tests’.
Non-invasive test-and-treat strategies are widely recommended in the primary care setting. The
choice of appropriate test depends on the pre-test probability of infection, the characteristics of
the test being used and its cost-effectiveness.