Management of Helicobacter pylori infection in Vietnam

Abstract

Aims: The general aim of the present study was to assess the usefulness of Helicobacter pylori eradication therapy in the long-term outcome of peptic ulcer disease in a developing country such as Vietnam. In addition, we also wanted to elaborate a simple and efficacious treatment regimen and to evaluate the accuracy of the non-invasive ELISA method for use in Vietnam.

Methods: In a randomised clinical study in Vietnam, 296 patients with peptic ulcer disease and H. pylori infection were included. The efficacy of a standard twice-daily PPI-based therapy with tinidazole and clarithromycin was compared to once-daily treatments with and without PPI, in relation to antibiotic resistance. The long-term H. pylori and peptic ulcer status was assessed with gastroscopy, serology and/or culture after 11 months. Accuracy of ELISA for use in Vietnam was evaluated by comparing specificity and sensitivity when using Vietnamese versus Swedish antigens. Culture and immunoblot was used as reference methods.

Results: Primary resistance to clarithromycin and metronidazole was 1.0% and 76.1 %, respectively. In patients with strains sensitive to both clarithromycin and tinidazole, the once-daily antibiotic therapy without PPI achieved an H. pylori eradication of 90.9%, compared to 95.0% in the once-daily therapy group with PPI and 100.0% in the standard triple therapy group. The corresponding results in patients with high-level metronidazole resistant strains were 20.8% in the antibiotics-only group, 58.1% in the once-daily with PPI group and 95.3% in the standard therapy group. Overall reinfection with H. pylori one year following successful eradication was 23.5% and 89.8% of the patients were free of peptic ulcer disease. In the patients who were not successful treated, 85.1 % were still H. pylori positive and 58.7% were free from peptic ulcer after one year. ELISA based on Vietnamese antigens showed a specificity of 96.4% and sensitivity of 91.0% compared to 96.4% and 69.4%, respectively, when Swedish antigens were used.

Conclusion: H. pylori eradication therapy is useful in preventing recurrence of peptic ulcer disease also in developing countries such as Vietnam, despite a higher reinfection rate than in developed countries. Once-daily antibiotic treatment with tinidazole and clarithromycin is highly effective in H. pylori treatment in the absence of antibiotic resistance. However, the standard twicedaily triple therapy with PPI still seems to be the most cost-effective option as it is shown to overcome the high rate of high-level metronidazole resistance found in Vietnam. Finally, ELISA with local H. pylori antigens is shown to be an accurate and valid non-invasive method to be used in Vietnam for diagnosis of H pylori infection in patients and in epidemiological studies.