Long-term re-infection rate after Helicobacter pylori eradication in Bangladeshi adults

Abstract

Background and aim: Bangladesh is a developing country with a very high prevalence of Helicobacter pylori infection, which has been ascribed to overcrowding and poor sanitary conditions. It has generally been accepted that the re-infection rate is higher in countries with a high prevalence of H. pylori infection. Short-term follow-up studies support this assumption but no long-term studies are available to confirm or refute this assertion. The present study was aimed to define the long-term H. pylori re-infection rate (6 years after successful eradication) in duodenal ulcer patients.

Methods: In a previous study, 90 patients were successfully eradicated for H. pylori and followed-up for 24 months. 17/90 were found to be re-infected (18% re-infection rate per year in the first 12 months) [Gastroenterology 2001;792-798]. The remaining 73 patients were targeted for long-term follow-up. 26/73 were lost to follow-up; 6 symptomatic patients were tested H. pylori positive in the period between 24 and 60 months post-eradication. The remaining 41 patients were evaluated 72 months after successful eradication. The evaluation included clinical history taking, a (13)C-urea breath test (UBT), and endoscopy.

Results: Of the 41 H. pylori-eradicated patients analyzed after 72 months, 16 were H. pylori-positive. If the 6 patients, who were tested positive between 24 and 60 months, are added, the total re-infection cases amount to 22 subjects in the period between 24 and 72 months. Therefore, an overall annual re-infection rate 6 years after eradication of 5.02% can be calculated. Six of the 23 symptomatic patients had duodenal ulcer relapse, 5/6 were H. pylori re-infected and one was H. pylori-negative at 72 months post-treatment.

Conclusion: The long-term annual H. pylori re-infection rate in Bangladeshi adults is markedly higher than in Western countries but lower than anticipated. In this study, duodenal ulcer relapse is clearly related to H. pylori re-infection.