Medical Health Encyclopedia

Specific Screening Tests for H. Pylori. The following are the screening tests used or under investigation for H. pylori.

• Breath Test. A simple test called the carbon isotope-urea breath test (UBT) can identify up to 99% of people who harbor H. pylori. Up to two weeks before the test the patient must be off any antibiotics, bismuth-containing agents (such as Pepto Bismol), and proton-pump inhibitors. As part of the test, the patient swallows a special substance containing urea (a compound in mammals metabolized from nitrogen) that has been treated with carbon atoms. If present, the H. pyloribacteria convert the urea into carbon dioxide, which is detected and recorded in the patient's exhalation after ten minutes.
• Blood Tests. Blood tests are used to measure antibodies to H. pylori, with results available in minutes. Diagnostic accuracy is reported at 80% and 90%. One such important test is called enzyme-linked immunosorbent assay (ELISA). An ELISA test of the urine is also showing promise in children.
• Stool Test. A test to detect genetic fingerprints of H. pylori in the feces appears to be as accurate as the breath test for initial detection of the bacteria and for detecting recurrences after antibiotic therapy.

It should be noted that such tests are not as accurate as endoscopy, an invasive procedure, which is needed to confirm a diagnosis of H. pylori. The breath and stool tests, however, can be particularly useful after treatment to determine if patients are cured.

Text Continues Below

---

Managing the Test Results: Test and Treat. Depending on the results of the screening tests, some doctors take the following steps:

• Approach for Non-Infected Individuals. People who do not have evidence of H. pylori on a blood test or breath are typically given a four-week course of acid-suppressing medication, usually proton-pump inhibitors (PPIs), such as omeprazole (Prilosec).
• Approach for H-Pylori Infected Individuals. Patients who have evidence of bacterial infection are given antibiotics. If this does not relieve symptoms, they are given another six-week course of omeprazole (Prilosec). (Whether to give antibiotics to infected patients with non-ulcer dyspepsia is controversial, however, and discussed in the section What Are the Guidelines for Treating Peptic Ulcers Caused by H. pylori?)