Comparison of stool immunoassay with standard methods for detecting Helicobacter pylori infection.

Helicobacter pylori is the cause of type B gastritis and associated with peptic ulcer disease. Various methods are available for detecting H pylori, but all have limitations. H pylori infection can be diagnosed by tests requiring endoscopy (rapid urease test, histology, culture) and by non-invasive tests (carbon-13 urea breath test, serology, stool tests). The urea breath test is currently the most important test for follow up after H pylori treatment. Serology is widely used for screening patients for H pylori infection; it has a good sensitivity, is fast, and relatively inexpensive. However, the urea breath test is expensive and requires specialised equipment, and serological tests cannot be used after H pylori treatment and may have a lower specificity. Most patients infected with H pylori are treated by general practitioners, who need an easy test for it. Recently, an immunoassay has been developed that can detect H pylori antigen in human faeces, but it has not been validated for clinical use. We studied patients undergoing routine endoscopy to determine sensitivity and specificity of this immunoassay in comparison with standard methods.