Risk factors associated withHelicobacter pyloriinfection among children in a defined geographic area

Factors influencing the pattern ofHelicobacter pyloriinfection among children living in adjacent urban and rural areas of northern Sardinia, Italy, were compared. The seroprevalence ofH. pyloriinfection was 22% (625 of 2810 children) in the study population and was significantly higher among children in rural areas (37%) than in urban areas (13%) (odds ratio [OR], 3.8; 95% confidence interval [CI], 3.2–4.7;P<.005). This difference was consistent within each age group. In rural areas, children who had dogs were at greatest risk forH. pyloriinfection (OR, 1.8; 95% CI, 1.3–2.6;P<.05). No association was seen betweenH. pylorisero-positivity and a history of breast-feeding. Urban children attending day care centers had a higher prevalence of infection (17%) than did those who never attended (12%) (OR, 1.5; 95% CI, 1.1–2.0;P<.05). The epidemiology ofH. pyloriinfection is complex; even within the same geographic area, different factors influence acquisition ofH. pyloriinfection.