Evaluation of a new urease reagent strip for detection of Helicobacter pylori in gastric biopsy specimens

OBJECTIVES: Determine sensitivity and specificity of a new urease reagent strip (URS) test for detection of Helicobacter pylori in gastric biopsy specimens. METHODS: Six paired biopsy specimens were obtained from the greater curvature of the distal antrum, the lesser curvature near the incisura, and the corpus along the greater curvature during 66 procedures on 59 patients with endoscopic findings of gastric antral mucosal erythema or erosions, or gastric or duodenal ulcers. One biopsy from each site was tested with the URS. The second was evaluated with histology. A final antral biopsy was evaluated with a urea/gel test. RESULTS: Twenty-eight of the 66 cases were histologically positive, with H. pylori observed in at least one of the three biopsy sites. The URS test correctly identified all 28. Of 193 individual biopsy specimens, 78 were positive for H. pylori. The URS correctly identified 77. Sensitivity was 0.99, specificity 0.95, positive predictive value 0.93, negative predictive value 0.99, and kappa 0.92. Average time to positive was 20 min. Twenty-seven antral biopsies were histologically positive for H. pylori. The URS test correctly identified all 27, whereas the urea/gel test correctly identified 21. For antral sites, URS sensitivity was 1.00 and specificity 0.95 versus urea/gel test sensitivity of 0.75 and specificity of 1.00. CONCLUSIONS: In this sample, the URS test is as accurate as histology in diagnosing H. pylori infections, and it provides results in less time and at a lower cost than histology.