Testing Methods

There are a several standard tests for assessing the presence of H. pylori. The main methods are:

  • Endoscopy (gastroscopy) – Endoscopy allows physicians to get a clear look at what is happening in the digestive tract as one or more histological samples of the stomach or intestinal lumen are removed for analysis. Endoscopy is rarely used for the detection of H. pylori alone; it is generally used to identify or rule out other stomach maladies. This testing option is invasive and expensive and requires special training and equipment.
  • Antibody Testing – Antibody testing relies upon the detection of IgG antibodies specific to H. pylori. Its advantages are its low cost and widespread availability. There are a number of appropriate testing mechanisms available: Western blot testing, immunochromatography, and enzyme-linked immunosorbent assay (ELISA). Some drawbacks, however, limit its use in clinical practice. A meta-analysis found its overall sensitivity and specificity to be 85% and 79%, respectively. Additionally, since some blood tests will appear positive for patients with a history of H. pylori infection, blood tests are not indicated in these cases. Regarding H. pylori blood tests, the ACG (American College of Gastroenterology) 2007 guidelines state that "… a positive test is no better than a coin toss in predicting the presence of active infection."
  • 13C-Urea Breath Test (UBT) – Ingested 13C labeled urea is metabolized in the presence of H. pylori to yield CO2. The labeled gas is absorbed across the gastric mucosa and is subsequently measured in the patient’s expired breath. The ACG (American College of Gastroenterology) claims that the urea breath test provides reliable means of identifying active H. pylori infection before antibiotic therapy. Moreover, the ACG asserts that the UBT is the most reliable non-endoscopic test to document eradication of H. pylori infection. In a recent UK study, an overwhelming number of patients said they would prefer a urea breath test over the other testing methods, in large part due to its high degree of accuracy.
  • Stool Antigen Test – This laboratory test can detect foreign proteins (antigens) in stool samples that are associated with H. pyloriinfection. Stool samples have high sensitivity and specificity, like the UBT, and they can also assess infection status following treatment.  However, stool samples require patient compliance, are inconvenient to handle, and results are not immediately known.