Presence of helicobacter pylori in a sibling is associated with a long-term increased risk of H. pylori infection in Israeli Arab children

Background and Objectives: We examined the dynamics of Helicobacter pylori infection between pre-school and school ages and compared the determinants of late acquisition of H. pylori infection with determinants of early and persistent H. pylori infection. Methods: ELISA was used to detect H. pylori antigens in stool specimens collected from children at preschool age (3-5 years) and from their mothers and siblings in 2004. The children were tested again for H. pylori at school age (6-9 years) in 2007-2009. Household and socioeconomic characteristics were obtained by interviews. Results: The prevalence of H. pylori infection increased from 49.7% (95% CI 42.8, 56.7) in 2004 to 58.9% (95% CI 51.8, 65.6) in 2007-2009. Among children tested in both examinations, 69 (49.3%) had persistent infection, 14 (10.0%) were new cases, 56 (40.0%) remained uninfected, and one (0.7%) had lost H. pylori infection. The approximate annual incidence of infection during 2004-2009 was 5%. Sibling's H. pylori positivity at baseline increased the risk for late acquisition of H. pylori infection; adjusted prevalence ratio (PR) 4.62 (95% CI 0.76, 28.23) (p =.09), while maternal education lowered the risk; adjusted PR 0.84 (95% CI 0.69, 1.01) (p =.06). Sibling's H. pylori positivity was the only significant variable associated with early and persistent H. pylori infection in multivariate analysis. Conclusions: Most H. pylori infections are acquired at preschool age and transient infection beyond this age is uncommon in this population. Helicobacter pylori-infected siblings are the major reservoir of H. pylori in early and late childhood demonstrating sustained intra-familial transmission of H. pylori.