Review article: invasive and non-invasive tests for Helicobacter pylori infection

There are two general ways in which a diagnosis of infection by Helicobacte r pylori can be made: by using either an invasive or non-invasive procedure . The invasive procedures involve an endoscopy and biopsy. A biopsy is esse ntial because often the mucosa may appear macroscopically normal but nevert heless be inflamed. A biopsy is obtained by histological examination, cultu re, polymerase chain reaction or detection of the presence of urease activi ty in biopsy material. The non-invasive tests that can be used to diagnose the infection are serol ogy, detection of labelled metabolic products of urea hydrolysis in the bre ath ((CO2)-C-13, (CO2)-C-14), the urine or the blood, and detection of H. p ylori antigen in a stool specimen. At present no single test can be relied upon to detect definitely colonization by H. pylori, and a combination of t wo is recommended if this is feasible. The choice of the test to be used is not straightforward and may vary according to the clinical condition and l ocal expertise.