The main tool used was serology,
but in a few studies, urea breath tests (UBT) or stool antigen tests (SAT) were used. In the United States, seroprevalence was performed on adults participating in the continuous National Health and Nutrition Examination Survey (1999–2000). The age standardized prevalence was high among Hispanic and African Americans compared to non-Hispanic whites. A significant decrease from the previous survey (1988–1991) was only observed in the non-Hispanic white population . A prevalence study conducted in 204 volunteer blood donors in Nassau (Bahamas) estimated a global prevalence of 58% for H. pylori infection, that is, comparable to other Caribbean territories . In Australia, a nationwide study including 1355 subjects showed Protein Tyrosine Kinase inhibitor a lower prevalence of H. pylori infection than in other developed countries. H. pylori infection varied significantly with age (ranging from 5 to 32% for those aged <40 and >70 years, respectively) and was higher among those born overseas as well as in the lowest socioeconomic areas . In Europe, Atezolizumab price H. pylori prevalence is still higher in the eastern than in the western countries. A serological survey carried out in 2318 patients presenting themselves at the emergency ward of Magdeburg hospital (former East Germany) had an overall prevalence of 44.4% (43.3%
of them with anti-CagA antibodies). A significant drop in seroprevalence was noted for those born after 1980 (<30 years of age) in the area. This can be explained by the housing program that was developed in the 1970s in this region allowing an improvement of the
socioeconomic conditions . A population-based study was designed in Denmark in primary care where 36,629 dyspeptic patients performed UBT at home at the discretion of their general practitioner, from 2003 to 2009. The prevalence was approximately 20% and declined over time during the course of the study, mainly between 2004 and 2007. Prevalence was higher for those older than 45 years than for the younger ones . In Belgium, the analysis of data from 22,612 dyspeptic patients over two decades (1988–2007) showed a global prevalence MCE of 37.7%, as determined by culture; the prevalence was lower in Western European patients than in North African patients with a significant decrease from 1988 to 2007: 36.2 and 15.2% for the former and 71.7 and 40% for the latter . In Israel, the age-adjusted H. pylori seroprevalence was 45.2% for Jewish participants. A difference was found according to age, as usual, but also from the region of the world from which participants originated (higher prevalence in Asia – Africa – South America than in North America – Western Europe – Australia) . In northern China, the seroprevalence in 798 healthy adults was 54.5% .