A Comparative Study of Serological and Stool Antigen Tests for Helicobacter pylori Infection Diagnosis

Background: Helicobacter pylori infection is prevalent worldwide and linked to gastrointestinal disorders, including gastritis, ulcers, and stomach cancer. Accurate diagnosis is crucial for effective treatment and monitoring. Non-invasive tests like serology and stool antigen testing are commonly used for diagnosis, but their comparative efficacy needs evaluation, especially in regions with varying prevalence rates. Methods: This comparative study included 120 participants from northern Iraq, comprising 60 with gastrointestinal disorders (mainly dyspepsia) and 60 healthy controls. Stool and serum samples were collected, and stool antigen tests and serological analysis (IgM) were performed. Results: The prevalence of H. pylori infection was higher in patients than controls, with 41.7% positive for stool antigen tests compared to 28.3% in controls (p = 0.003), and 37.5% positive for serology compared to 25.8% in controls (p = 0.001). Stool antigen testing demonstrated higher sensitivity in detecting active infection. Discussion: Non-invasive diagnostic methods like stool antigen tests offer advantages such as ease of implementation and unaffectedness by medications. In this study, stool antigen testing showed superior efficacy in detecting active H. pylori infection compared to serology, which may retain antibodies post-treatment, potentially leading to false positives. Conclusion: Both serological and stool antigen tests are valuable for diagnosing H. pylori infection, with stool antigen testing exhibiting higher sensitivity, especially in identifying active infections. The study recommends the use of stool antigen tests, particularly in dyspepsia patients, to determine active infection before initiating treatment, considering its superiority over serology. However, factors like sample handling and environmental conditions may affect stool antigen test results.