Non-invasive tests for the diagnosis of H. pylori infection.

Helicobacter pylori infection can be diagnosed by invasive techniques requiring endoscopy and biopsy (eg, histological examination, culture, polymerase chain reaction) and by non-invasive techniques such as serology, urea breath test, urine/blood test, 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 (eg, serology) are markers of exposure to H. pylori but do not indicate if active infection is ongoing; these are called "passive tests." Non-invasive test-and-treat strategies are widely recommended in primary care settings. The choice of an appropriate test depends on the pre-test probability of infection, the characteristics of the test being used, and the cost-effectiveness of the test. This article reviews available non-invasive tests.