Epidemiology of, and risk factors for, Helicobacter pylori infection among 3194 asymptomatic subjects in 17 populations

The cross sectional study describes the prevalence of infection with Helicobacter pylori as determined by a serodiagnostic assay in over 3000 asymptomatic subjects, in two age groups 25-34 years and 55-64 years, from 17 geographically defined populations in Europe, North Africa, North America, and Japan, using a common protocol for blood collection and serological testing. In all populations combined, the prevalence of infection was higher in the older age group (62·4%) than in the younger age group (34·9%). There was no difference in prevalence of infection between men and women. Subjects with higher education had considerably lower levels of infection (34·1%) compared with subjects with education up to secondary level (46·9%) or those with primary education only (61·6%). This trend was confined to the older of the two age groups. In contrast a trend of increasing prevalence of infection with increasing body mass index was confined to the younger of the two age groups. There was no effect of smoking or alcohol consumption on the prevalence of infection after adjusting for the other risk factors. There was considerable variation in the prevalence of infection between the 17 populations but, within populations, low education standard was consistently and positively associated with the prevalence of infection.