Urea breath test - Diagnosing H pylori Infection

One test that is widely available outside the US and under FDA evaluation in this country is the urea breath test, a sensitive, specific, and noninvasive test for H pylori. When an infected person swallows a dose of urea labeled with an isotope of carbon -- carbon-13 (13C) or carbon-14 (14C) -- H pylori in the gastric mucosa break down the labeled urea to form ammonia and labeled carbon dioxide. The carbon dioxide is absorbed into the bloodstream and excreted via the lungs. The patient then exhales into a device that measures the level of carbon dioxide. Of the two isotopes, 13C is safer because it is not radioactive, but it requires expensive instruments to detect it (a new generation of laser detectors may bring down costs). The 14C isotope uses a less expensive detector, but it emits beta radiation (although the amount emitted is a tiny fraction of the beta radiation that the average person is exposed to each year from natural sources). The urea breath test is specific for H pylori (it detects only urease-producing bacteria), it is sensitive (the labeled urea reaches a large area of the stomach and thus reflects total gastric urease activity), and the results can be reproduced.The urea breath:

Ultimately, the urea breath test should be approved and should be available for use in the doctor's office to provide a rapid diagnosis. In the mean time, doctors must rely on patient history, physical examination, lab tests, and radiography or endoscopy. Duodenal ulcers are usually benign, but gastric ulcers may be caused by a malignancy so endoscopic evaluation and biopsy of gastric ulcers are recommended, with repeat endoscopy to confirm healing.

source: Silverstein MD. Gastroent.