Recurrence of infection and diversity of Helicobacter pylori strains in an adult population in Mexico treated with empirical standard triple therapy

Abstract

Background: After eradication treatment for Helicobacter pylori (H. pylori), infection could recur due to recrudescence or re-infection. The objective of this study was to determine the recurrence of H. pylori infection and identify virulent H. pylori strains one year after eradication with standard triple therapy. Material and methods: A quasi-experimental study was performed that included a patient population with digestive diseases associated with H. pylori who had received standard triple therapy. Cultures and polymerase chain reaction (PCR) was performed on gastric biopsies for strain identification in all patients prior to eradication treatment and those with a positive carbon-14 breath test one year after eradication treatment. Statistical analysis was performed using the Student's t-test and Fisher's exact test; statistical significance was set at 0.05. Results: One hundred and twenty-eight patients were studied, 51 (39.8%) were male and 77 (60.2%) were female with an average age of 54.8 years (DE 13.8). There was an annual recurrence of H. pylori infection in 12 (9.3%) patients. An annual re-infection and recrudescence occurred in nine (7%) and three (2.3%) patients respectively. The recrudescence rate for antigenic protein (cagA) was 1/30 (3.3%) patients and 2/112 (1.8%) patients for vacuolating cytotoxin (vacA). The re-infection rate for cagA was 3/30 (10%) patients and 6/112 (5.3%) patients for vacA. Conclusions: The recurrence of infection in this study was higher than that recorded in developed countries with a low prevalence of H. pylori and lower than that recorded in developing countries with a higher prevalence of H. pylori. The cagA or vacA s2/m2 strains were isolated after re-infection and recrudescence.

Keywords

• Recurrence
• Helicobacter pylori
• Eradication