[Non-invasive analyses for the diagnosis of Helicobacter pylori infection. A critical review of the literature].

Helicobacter pylori (H. pylori) infection may be diagnosed by means of invasive techniques requiring endoscopy and biopsy (histological examination, rapid urease test, culture, polymerase chain reaction) and by non-invasive techniques (urea breath test, detection of specific antibodies in the serum or urine, detection of the H. pylori antigen in a stool specimen). Some non-invasive tests detect active infection e.g. the urea breath test and the stool antigen test and are called active tests. Other non-invasive tests are markers of exposure to H. pylori (e.g. serology or urine) but do not indicate whether active infection is ongoing and are called passive tests. Non-invasive tests and treatment strategies are widely recommended in primary care settings and the choice of the appropriate test depends on the pre-test probability of infection, the characteristics of the test being used and its cost-effectiveness. The available non-invasive tests are reviewed in this article.