The prevalence of active H. pylori infection on admission was 38% as detected by urea breath test, and declined to 8% on the third day, and to 0% on the seventh day after admission as a result of antibiotic treatment. Stress ulcer-related upper gastrointestinal bleeding occurred in 1.0% (3 of 300) of the patients; none were infected with H. pylori on admission or at the time of bleeding.