From the Guidelines
H. pylori testing should be done using either the Urease Breath Test (UBT) or stool antigen test for initial diagnosis, as they have high sensitivity and specificity (>90%). When considering the diagnosis of H. pylori infection, several testing options are available, including non-invasive methods like the UBT, stool antigen test, and blood antibody test, as well as invasive methods requiring endoscopy such as rapid urease test, histology, and culture 1. The UBT and stool antigen test are preferred for initial diagnosis due to their high accuracy, with the stool antigen test having a weighted mean sensitivity of 93.2% and specificity of 93.2% in pretreatment clinical settings 1. Some key points to consider when testing for H. pylori include:
- Testing should be done at least 2 weeks after stopping proton pump inhibitors and 4 weeks after antibiotics, as these medications can cause false-negative results.
- After treatment, confirmation of eradication is typically done with either the UBT or stool antigen test at least 4 weeks after completing therapy to ensure accurate results.
- Blood antibody tests are less reliable for active infection as antibodies can remain positive for months after successful treatment. The European Helicobacter Pylori Study Group has recommended the use of either the UBT or stool testing in the initial diagnosis of H. pylori infection 1. In the post-therapy setting, the polyclonal stool test may be a viable alternative to breath testing after treatment, with a weighted mean sensitivity of 92.1% and specificity of 87.6% 1.
From the Research
H pylori Test Overview
- The H pylori test is used to diagnose Helicobacter pylori infection, which can cause peptic ulcers, non-ulcer dyspepsia, and other conditions 2.
- Non-invasive tests for H pylori infection include the urea breath test (UBT), serology, and stool antigen test (SAT) 3, 2, 4.
Types of H pylori Tests
- Urea breath test (UBT): a non-invasive test that detects active H pylori infection 2, 5, 6.
- Serology: a test that detects antibodies against H pylori, indicating past or present infection 2, 4.
- Stool antigen test (SAT): a non-invasive test that detects H pylori antigen in stool samples 3, 2, 4.
Diagnostic Accuracy of H pylori Tests
- The urea breath test (UBT) has high diagnostic accuracy, with a sensitivity of 0.94 (95% CI 0.89 to 0.97) and a specificity of 0.90 (median from studies across the four tests) 2.
- The stool antigen test (SAT) has a sensitivity of 0.83 (95% CI 0.73 to 0.90) and a specificity of 0.90 (median from studies across the four tests) 2.
- A newly developed SAT showed 97.3% sensitivity and 99.3% specificity for diagnosing H pylori infection in a medical checkup setting 3.
Clinical Recommendations
- The choice of H pylori test depends on the pre-test probability of infection, test characteristics, and cost-effectiveness 4.
- Proton pump inhibitor therapy can lead to false-negative H pylori test results, and treatment should be stopped for 1-2 weeks prior to testing if possible 5.
- The 13C-UBT is preferred over the 14C-UBT due to its non-radioactive nature and higher diagnostic accuracy 6.