Endoscopic methods for the diagnosis of Helicobacter pylori.

This article reviews endoscopic methods for the diagnosis of Helicobacter pylori. At the time of endoscopy certain findings (gastroduodenal ulceration and/or antral nodularity) may be highly suggestive of H. pylori infection. Endoscopic acquisition of gastric biopsies, however, leads to a definitive diagnosis of infection on the basis of both direct and indirect tests. Direct tests include culture and histological detection (considered the gold standard). There are a variety of stains available for the detection of H. pylori; their choice is influenced by local expertise and the clinical situation. If at least three biopsies are obtained from non-adjacent gastric sites, incorrect assessment of H. pylori status should be rare. Indirect methods utilize the detection of urease. The three biopsy rapid urease tests commercially available in the USA have similar performance characteristics, except that two are gel tests requiring up to 24 h to read, while one is a strip test which is read up to 1 h. Specificity is excellent for these tests, while sensitivity is more variable. Rapid urease tests are the endoscopic tests of choice for initial evaluation due to their low cost.