Does Helicobacter pylori (H. pylori) require retesting after treatment?

From the Guidelines

H. pylori should be retested after treatment to confirm eradication, as recommended by the most recent guidelines. This follow-up testing is crucial for ensuring that the infection has been successfully eradicated, which is essential for reducing the risk of peptic ulcer recurrence, preventing complications, and potentially reducing gastric cancer risk in high-risk populations 1. The testing should be performed at least 4 weeks after completing antibiotic therapy and at least 2 weeks after stopping proton pump inhibitors (PPIs).

Testing Methods

The most common testing methods for post-treatment evaluation include:

• The urea breath test, which is particularly reliable for confirming eradication, with sensitivity and specificity exceeding 95%
• The stool antigen test
• In some cases, endoscopy with biopsy

Retesting is important because H. pylori eradication fails in approximately 10-30% of patients due to antibiotic resistance, poor medication adherence, or other factors 1. If the follow-up test remains positive, a different antibiotic regimen should be prescribed, typically using medications not included in the initial treatment approach.

Importance of Retesting

Successful eradication of H. pylori significantly improves patient outcomes, including:

• Reducing the risk of peptic ulcer recurrence
• Preventing complications like bleeding
• Potentially reducing gastric cancer risk in high-risk populations Therefore, retesting for H. pylori after treatment is a crucial step in ensuring the best possible outcomes for patients.

From the FDA Drug Label

H pylori eradication was defined as 2 negative tests (culture and histology) at 4 to 6 weeks following the end of treatment. The answer to the question is yes, H pylori needs to be retested after treatment, as evidenced by the definition of eradication which requires 2 negative tests at 4 to 6 weeks following the end of treatment 2.

• Retesting is necessary to confirm eradication of H pylori.
• The timing of retesting is specified as 4 to 6 weeks after the end of treatment.

From the Research

Retesting for H. pylori after Treatment

• The need for retesting after treatment is supported by studies that evaluate the diagnostic accuracy of various tests for H. pylori infection 3, 4, 5.
• A study published in the Journal of Gastroenterology in 2009 found that a monoclonal stool antigen test was useful for diagnosing H. pylori eradication 4 weeks after the end of treatment, with a sensitivity of 91.6% and specificity of 98.4% 3.
• Another study published in the United European Gastroenterology Journal in 2023 assessed the use of non-invasive stool tests for verification of H. pylori eradication and clarithromycin resistance, and found that stool H. pylori antigen testing on fecal immunochemical test samples had similar accuracy to dry fecal samples for eradication assessment 4.
• The Expert Review of Gastroenterology & Hepatology published a study in 2007 that discussed the importance of accurate diagnosis and appropriate therapy for H. pylori infection, and noted that 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 6.
• A prospective cohort study published in Internal Medicine in 2024 evaluated the accuracy of a novel stool antigen test for H. pylori infection in a medical checkup setting, and found that the test had high sensitivity and specificity for diagnosing current infection 7.
• A study published in Diagnostic Microbiology and Infectious Disease in 2008 compared the diagnostic accuracy of a rapid lateral flow stool antigen immunoassay and a (14)C-urea breath test for the diagnosis and eradication of H. pylori infection in children, and found that the (14)C-urea breath test was more reliable than the stool antigen test for confirming eradication of H. pylori infection 5.

Diagnostic Tests for H. pylori

• The urea breath test (UBT) and stool antigen test (SAT) are noninvasive tests that are commonly used to diagnose H. pylori infection 6, 7, 5.
• The UBT is considered a reliable test for confirming eradication of H. pylori infection 5.
• The SAT is a useful test for diagnosing H. pylori infection, but its accuracy may vary depending on the specific test used and the population being tested 3, 4, 7.
• Other diagnostic tests, such as endoscopy and histology, may also be used to diagnose H. pylori infection, but are more invasive and may not be necessary for all patients 6, 5.