Seroincidence of Helicobacter pylori Infection in a Cohort of Rural Bolivian Children: Acquisition and Analysis of Possible

High seroprevalence rates for Helicobacter pylori are reported in developing countries, yet few seroincidence studies exist that determine age of initial acquisition and risk factors for H. pylori seroconversion. Two H. pylori serosurveys were conducted in August 1996 and November 1997. Of 188 children aged 21 months to 6 years who were seronegative in the first survey, 44 (23%) had seroconverted at follow-up, yielding an 18% annual seroincidence. The largest increase in seroincidence occurred between children aged 2 years (10%) and children aged 3 years (32%). Use of a lidded, narrow-mouthed water vessel was protective against serocon-version (odds ratio [OR], 0.3; 95 % confidence interval [CI], 0.1–0.8), and the presence of another H. py-lori–seropositive sibling in the household was a risk factor for seroconversion (OR, 3.1; 95 % CI, 1.3–8.7). Although not a randomized intervention trial, this study suggests that the use of a narrow-mouthed water vessel may prevent the transmission of H. pylori in households in developing countries. Helicobacter pylori is a leading cause of antral gastritis in both adults and children [1]. Infection with H. pylori, which may be lifelong if untreated, causes gastritis, duo-denal and gastric ulcers, and stomach cancer [2–4]. IgG antibodies specific for H. pylori indicate past or presen