Diagnosis of Helicobacter pylori infection.

A number of reliable methods are currently available for the diagnosis of Helicobacter pylori infection. These diagnostic tests can be classified into invasive methods that require endoscopy and gastric biopsy, and noninvasive methods. Invasive methods include gastric mucosal biopsies at endoscopy for bacteriologic culture, histology, and the rapid urease test. Noninvasive methods include the urea breath test and serologic tests. Each of these diagnostic tests has its advantages and disadvantages. Histologic examination remains the gold standard for diagnosis. It can also detect coccoidal forms of the bacteria and be used to assess the severity of gastritis. Culture of H pylori should be performed if antibiotic sensitivity of the organism is required. A rapid urease test is the quickest test for H pylori status. The urea breath test detects urease activity in the entire stomach, thus eliminating the possibility of a sampling error, which occurs in random gastric biopsies. Serologic tests using either ELISA or latex-agglutination methods are excellent for diagnosis of H pylori infection, but not useful for monitoring effects of therapy. Recently, the polymerase chain reaction has been applied to fixed-tissue biopsies, as well as body secretions in the diagnosis of H pylori infection.