[30] in a review of a huge database of all biopsies collected in a central laboratory in the USA reported a H. pylori prevalence of only 7.5%. Several studies have focused on specific disease groups to determine the possible relationship with H. pylori infection [33–38] (Table 2). Kirchner et al. [33] did not find a significant difference in H. pylori seroprevalence between liver cirrhotic and noncirrhotic patients. Senbanjo et al. [34] compared the seroprevalence of H. pylori between children with and without sickle cell disease and found the prevalence to be high in both. High prevalence Selleckchem EX527 of H. pylori infection was seen among

morbidly obese patients undergoing bariatric surgery (85.5%) [35] and patients with myelodysplasia (75.3%) [36]. On the other hand, an inverse relationship with HIV infection was noted in a study from Brazil [37]. This marked disparity has been observed previously [39–41], but the reason for it remains unclear. Schimke et al. [38] reported H. pylori seroprevalence of 62.0% among a cohort of patients with type 2 diabetes Transmembrane Transporters activator mellitus. Two studies looked at time trend differences

[31,42]. Nakajima et al. [42] studied subjects who went for annual health check at their hospital and reported a drop in H. pylori seroprevalence from 70% to 50% over a 17-year period (1988–2005) and along with this, a decline in the prevalence of peptic ulcer disease (PUD) and gastric cancer. In an endoscopy-based study from the USA with relatively small numbers, McJunkin et al. [31] also reported a dramatic drop in H. pylori prevalence (from 65.8% to 6.8%) and PUD (from 38.8% to 5.6%) over an 11-year period. There was only one study reporting on incidence of H. pylori infection. In this study by Muhsen et al. [43]., a cohort of Israeli Arab children at preschool age was tested for H. pylori infection using SAT and the test was repeated at school age. The prevalence of H. pylori infection was 49.7% and 58.9% at preschool age and school age, respectively. Among children

上海皓元医药股份有限公司 tested in both examinations, there were fourteen new H. pylori infections among seventy previously uninfected children (20%) over a 4-year period, giving an annual incidence of 5%. Transmission of H. pylori is still not entirely clarified, but human-to-human spread through oral–oral or fecal–oral route is thought to be the most plausible. Several studies looked at the spread of H. pylori infection between siblings [20,26,43–45]. Two of these were well-conducted cohort follow-up studies [43,44]. In the study by Muhsen et al. [43], Israeli Arab children aged 3–5 from three villages in northern Israel were followed up for 3–4 years. Having H. pylori-infected sibling was identified as an independent risk factor for both “early” and “persistent”H. pylori infection as well as late acquisition of the infection. In a second study, Cervantes et al. [44] reported that persistent H.