Effect of Age on the Frequency of Active Campylobacter pylori Infection Diagnosed by the 13Urea Breath Test in Normal Subjects and Patients with Peptic Ulcer Disease

We studied the frequency of active Campylobacter pylori infection in persons from North America (n = 53) or the People's Republic of China (n = 15) who had no gastrointestinal symptoms or a history of ulcer disease and in patients with active or recently active duodenal or gastric ulcers diagnosed by endoscopy (n = 105). C. pylori infection was significantly (P less than .001) more frequent in patients with peptic ulcers (88%) than in the normal group (45%). An age-related increase in the frequency of C. pylori infection in subjects with no gastrointestinal symptoms paralleled the known age-related increase in prevalence of gastritis. The frequency of C. pylori infection in patients with duodenal ulcers was greater than 80%, irrespective of age. C. pylori infection was more common in the Chinese group (age, 20-39 y) than in the North American group of the same age (60% vs. 24%). Association of C. pylori with specific diseases should not be inferred without knowing the prevalence of C. pylori infection in reference populations of the same age and ethnic background.