Dr Calvet and colleagues evaluated the diagnostic usefulness of a delayed test in initially negative patients.
The research team assessed the reliability and sensitivity of the rapid urease test, or histology to diagnose Helicobacter pylori during emergency endoscopy.
The team also evaluated the reliability and sensitivity of a combination of both to diagnose H pylori during emergency endoscopy.
Records of patients with ulcer bleeding in a large clinical practice series were reviewed from 1995 to 2000.
Patients with initially negative tests were retested 4 to 8 weeks after the bleeding episode.
|The prevalence of H pylori was 95% in duodenal ulcers|
|Alimentary Pharmacology & Therapeutics|
The team also determined the efficacy of delayed Urea Breath Test in detecting missed infection.
The study included 429 patients.
The team found that a delayed second test detected H pylori infection in 79% of initially negative patients.
The sensitivity for detecting H pylori was 76%, 78% and 86% for urease, histology and their combination, respectively.
The researchers observed that the prevalence of H pylori was 95% in duodenal and 88% in gastric ulcer.
Only 1 test was performed in 17 of the 32 patients who were considered negative.
Dr Calvet's team commented, “Not even the combination of a negative urease and histology in the initial endoscopy is able to rule out infection in bleeding ulcer patients.”
“A delayed test should be performed to rule out H pylori infection completely.”