Age was a risk factor for Helicobacter pylori reinfection in children In the youngest age group of 3 - 4 year-olds 55.4% (95% CI 28 - 83) were reinfected within one year, with the rates decreasing to 40.7% (95% CI 21 - 61) in 5 - 6 year-olds, 29.7% (95% CI 8 - 52) in 7 - 8 year-olds and 12.8% (95% CI 5 - 21) in the 9 - 15 year-olds (p=0.0001).