Supplement Abstracts Submitted for the 73rd Annual Scientific Meeting of the American College of Gastroenterology: STOMACH
Purpose: Although the prevalence of H. pylori infection is believed to be decreasing in industrialized countries and in emerging economies, recent data from the U.S. are unavailable. This study was designed to evaluate the prevalence of H. pylori infection in gastric biopsy specimens from a large nationwide sample of subjects who underwent esophagogastroduodenoscopy between 4/2007 and 3/2008.
Methods: We analyzed electronic data from Caris Diagnostics, a specialized gastrointestinal pathology group receiving specimens from gastroenterologists operating in community-based endoscopy centers in 40 states. For each patient, the database includes demographic and clinical information, summary of the endoscopic report, site of origin, and the histopathologic report for each biopsy. To identify the records for eligible biopsy specimens we extracted data from all cases with a report date within the 12-month period from 4/01/07 to 3/31/08. Data were stored in a Microsoft Access database. Statistical calculations were performed using SigmaStat 3.5; chi-square test, Student's t-test and the Mann-Whitney Rank Sum Test for non-parametric data were used as appropriate. A P value < 0.05 was considered significant.
Results: We extracted 78,909 unique patients (48,432 women, 61.4%) who had undergone gastric biopsy. Their median age was 56 years (range 0–103). Chronic Active Gastritis (CAG, the quintessential histopathologic expression of H. pylori infection) was diagnosed in 11,084 patients (14.05%) and H. pylori organisms were detected histologically in 9,492 subjects (12.03%, median age 56 years; 57.6% women). The prevalence of infection was 5.2% in children (<18) and 11.6% in elderly patients (>70); the peak prevalence rate (12.3%) was in patients aged 45 to 65. A high prevalence of H. pylori (>18%) was found in cases from NY and IL, as well as Puerto Rico (29%); the lowest rate was in KS (3.8%). Intestinal metaplasia (IM), detected in 7.3% of all patients, was twice as prevalent in H. pylori-positive (12.6%) than in H. pylori-negative (6.5%) subjects (OR = 2.04; 95% CI 1.90–2.18). Irrespective of their H. pylori status, patients with IM were older than those without (65 vs. 56, P < 0.0001).
Conclusion: This large nation-wide study indicates that the U.S. population has a low prevalence of H. pylori infection, comparable to that of other industrialized countries. As expected, children had less than half the prevalence of adults. In contrast to serologic studies, infection rates in older Americans were lower than those of middle-aged subjects, suggesting that frequent antibiotic treatments and the widespread chronic use of proton-pump inhibitors may result in the unintentional eradication of the infection in large segments of the population.