[Diagnosis of Helicobacter pylori infection]

Helicobacter pylori can be diagnosed by invasive and non-invasive methods. The invasive method most frequently used in France is histology which also allows the detection of stomach lesions. Culture or PCR which allow detection of the bacterium gives the possibility to test its antimicrobia susceptibility (for PCR, only resistance against clarithromycin except for one particular kit which also tests against fluoroquinolones) is only used in case of treatment failure, while if used as a first intention, it would give important indications for treatment. The noninvasive method mostly used is the 13C urea breath test, with excellent accuracy, which is essentially used to control H. pylori eradication one month or more after stopping treatment. The need for serology has increased due to the rise in the number of patients who received a treatment before being referred to a specialist. It is an ideal method for screening purposes, including H pylori eradication to prevent gastric cancer, but all of the currently available kits do not have the same accuracy.