Prevalence of Helicobacter pylori infection in different ethnic groups in New Zealand children and adults

BACKGROUND: Helicobacter pylori infection is a major risk factor for peptic ulcer disease and gastric cancer. A study of patients with dyspepsia attending for gastroscopy showed significant differences in H. pylori seropositivity between ethnic groups. AIMS: To determine the prevalence of H. pylori in children and adults in the community in different ethnic groups and to identify risk factors for infection. METHODS: Serum samples (324) were randomly selected from a cross-sectional survey of 11-12 year old school children with a high proportion of Maori and Pacific Island groups. Serum samples (579) were randomly selected from a cross-sectional workforce survey of 5677 participants aged 40-64 years. Serum samples were tested for H.pylori IgG. RESULTS: The percentage seropositivity in 11-12 year old children was European 7%, Maori/part Maori 21%, all Pacific Island groups 48% and for the workforce survey 35.8%, 57.4% and 73.2% respectively. Compared with Europeans the increased relative risk of seropositivity for H.pylori in Maori and Pacific Island participants was significant after adjusting for age and socio-economic status (1.43 [1.13, 1.80] and 1.76 [1.43, 2.18]) respectively. The relative risk of H.pylori infection significantly increased with age, lower socio-economic status and lower household income, but was not significantly associated with gender, alcohol or cigarette use. CONCLUSIONS: The high seroprevalence of H.pylori in Maori and Pacific Island groups is consistent with the differences in incidence of gastric cancer. H.pylori continues to be a common infection in Maori and Pacific Island school children. Ethnicity appears to be a risk factor for H.pylori independent of socio-economic status.