Background: Helicobacter pylori infection rates in duodenal ulcer (DU) patients may be lower than previously estimated.
Aim: To review the real prevalence of H. pylori-negative DUs and its possible causes.
Methods: Bibliographical searches in MEDLINE looking for the terms 'H. pylori' and 'duodenal ulcer'.
Results: Mean prevalence of H. pylori infection in DU disease, calculated from studies published during the last 10 years including a total of 16 080 patients, was 81%, and this figure was lower (77%) when only the last 5 years were considered. Associations with H. pylori-negative DU were: (1) False negative results of diagnostic methods, (2) NSAID use (21% in studies with <90% infection rate), (3) Complicated DU (bleeding, obstruction, perforation), (4) Smoking, (5) Isolated H. pylori duodenal colonization, (6) Older age, (7) Gastric hypersecretion, (8) Diseases of the duodenal mucosa, (9) Helicobacter'heilmanii' infection and (10) Concomitant diseases.
Conclusion: In patients with H. pylori-negative DU disease, one should carefully confirm that the assessment of H. pylori status is reliable. In truly H. pylori-negative patients, the most common single cause of DU is, by far, the use of NSAIDs. Ulcers not associated with H. pylori, NSAIDs or other obvious causes should, for the present, be viewed as 'idiopathic'. True idiopathic DU disease only exceptionally exists.