In 1983, Warren and Marshall described the Gram-negative, spiral-shaped microaerophilic bacterium, Helicobacter pylori (H. pylori) that colonises the human stomach. Numerous studies have confirmed an aetiologic role of H. pylori in the development of chronic gastritis, peptic ulcers, gastric mucosa-associated lymphoid tissue lymphoma and gastric cancer.[1–4] In 1994, the international agency for the research of cancer (IARC) classified H. pylori as a class I (definite) carcinogen for gastric cancer.H. pylori gastritis has been defined as an infectious disease, whose modes of transmission include oral-oral, faecal-oral and gastro-oral. The global prevalence of H. pylori infection has remained high, especially in countries with low socioeconomic status and poor sanitary conditions.[8,9] While the successful eradication of H. pylori can prevent development and progression of H. pylori-associated diseases, the efficacy of H. pylori treatment regimens has decreased because of increasing antibiotic resistance.H. pylori recurrence also remains an unsolved problem.
The successful eradication of H. pylori results in healing of chronic active gastritis and prevents progression to gastric atrophy, improves dyspeptic symptoms, heals gastric and duodenal ulcers, cures the majority of cases of early-stage (Lugano I/II) low-grade MALT lymphoma and reduces the incidence of gastric cancer.[6,10] Recurrence either as recrudescence (inadequate treatment) and reinfection eliminates the benefits of H. pylori eradication.
In the USA, the pooled H. pylori recurrence rate was 1.0% (95% CI, 0.1–3). However, it was 8.1% (95% CI, 6–10) in an Alaskan native population. The countries or regions with highest H. pylori recurrence rate reported were Turkey (21.3%, 95% CI 2–53), Ireland (15.2%, 95% CI 5–29), Bangladesh (14.4%, 95% CI 0.1–43), Mexico (11.7%, 95% CI 9–14), India (9.8%, 95% CI 1–23), Iran (7.3%, 95% CI 3–13), Chile (7.2%, 95% CI 2–15), Greece (6.2%, 95% CI 3–11) and Korea (5.4%, 95% CI 4–7). The countries or regions with lowest H. pylori recurrence rate were the The Netherlands (0.2%, 95% CI 0–2), Italy (0.6%, 95% CI 0–2), Norway (0.9%, 95% CI 0.2–2), Germany (1.4%, 95% CI 0.4–3), Australia (1.5%, 95% CI 0.3–3), Japan (2.0%, 95% CI 0.3–5), China (2.2%, 95% CI 0.8–4), Spain (2.2%, 95% CI 1–3), UK (2.4%, 95% CI 0.4–6), Canada (2.8%, 95% CI, 0.5–6) and Taiwan (2.8%, 95% CI, 0.5–6) (Figures S6-S27).
These results are consistent with prior studies showing that household hygiene and sanitary conditions are important and influential factors for H. pylori acquisition and recurrence