When should a patient with Helicobacter pylori (H. pylori) infection, diagnosed on esophagogastroduodenoscopy (endoscopy), who received triple therapy, undergo a follow-up test, specifically a stool antigen test?

From the Guidelines

For a patient with H. pylori infection who has completed triple therapy, the recommended follow-up test is the stool antigen test, which should be performed at least 6 weeks after starting eradication therapy and at least 2 weeks after proton pump inhibitor (PPI) withdrawal. This non-invasive test directly detects H. pylori antigens in the stool with high sensitivity and specificity. The waiting period is crucial because testing too early can lead to false-negative results, as the bacteria may be suppressed but not fully eradicated 1. Other follow-up options include the urea breath test (also requiring a similar wait) or repeat endoscopy with biopsy, but stool antigen testing is preferred due to its convenience, cost-effectiveness, and non-invasive nature.

Key Considerations

• The patient should avoid antibiotics and proton pump inhibitors for at least 2 weeks before testing, as these medications can interfere with test accuracy by temporarily suppressing bacterial load without achieving eradication 1.
• The choice of follow-up test should reflect the clinical indication, local availability, costs, and patient preferences.
• Noninvasive tests, such as the stool antigen test, are generally preferred over invasive tests like endoscopy with biopsy.

Rationale

The recommendation is based on the most recent and highest quality study, which suggests that the stool antigen test should be performed at least 6 weeks after starting eradication therapy and at least 2 weeks after PPI withdrawal 1. This study provides the most up-to-date guidance on the management of H. pylori infection and is published in a reputable journal. While other studies provide similar recommendations, they are either older or of lower quality, making the most recent study the best choice for guiding clinical practice 1.

Clinical Implications

The recommended follow-up test can help determine the success of eradication therapy and guide further management. A positive test result indicates that the infection has not been eradicated, and alternative treatment strategies may be necessary. A negative test result, on the other hand, suggests that the infection has been successfully eradicated, and the patient can be considered cured. By following the recommended follow-up testing schedule, clinicians can optimize patient outcomes and reduce the risk of complications associated with H. pylori infection.

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.

A patient with H. pylori infection who received triple therapy should undergo a follow-up test, specifically a stool antigen test, 4 to 6 weeks after the end of treatment to confirm eradication of H. pylori 2.

From the Research

Follow-up Testing for H. pylori Infection

• The optimal timing for a follow-up test, specifically a stool antigen test, after triple therapy for H. pylori infection is not explicitly stated in the provided studies.
• However, according to the study 3, cure of the infection was assessed by HpSA (H. pylori stool antigen immunoassay) 1 month after completion of therapy, suggesting that a follow-up test can be performed at least 1 month after treatment.
• Another study 4 assessed bacterial eradication 4-6 weeks after therapy had ended, which also supports the idea of performing a follow-up test around 1 month after treatment.
• It is essential to note that the timing of the follow-up test may vary depending on the specific treatment regimen and patient factors, and healthcare providers may recommend different follow-up schedules based on individual patient needs 5, 6, 7.