Validation of an in-house made rapid urease test kit against the commercial CLO-test in detecting Helicobacter pylori infection in the patients with gastric disorders

Background: h. pylori is a urease positive organism, and this activity in a gastric biopsy could be considered as a proof of the presence of h. pylori. for the reasons of high price and difficult accessibility to the commercial clo-test in iran, we designed an affordable equivalent test with high specificity, accuracy and availability. methods: biopsy samples from 80 symptomatic patients with gastrointestinal problems were included in this study. the results of our in-house made rapid urease kit were compared with the commercial clo-test up to 3 hours and 24 hours after inoculation of the biopsy samples. culture results and gram staining were proposed as gold standard. results: helicobacter pylori was isolated from 36 patients (45.0%) after cultivation of biopsy samples. after 3 hours, 33 (91.6%) cases of positive samples for h. pylori, showed urease positive reaction using both, in-house made and clo-test kits. however, 2 (5.5%) cases showed urease reaction at 24 hours using both the kits. the specificity of 100% was determined for both, in-house made and commercial clo-test kits after 3 hours. the sensitivity for both the kits was estimated at 97.1% after 3hours. however, after 24 hours, sensitivity and specificity of 97.1% and 88.64% was estimated for the in-house and 97.2 % and 95.4% for the commercial clo-test kits, respectively. conclusion: specificity and sensitivity of 100% and 97.1 % for up to 3 hours follow biopsy sampling, could be considered as an advantage for our in-house rapid urease kit. moreover, the rapid urease agar media designed in our lab is cost-effective with adequate sensitivity and specificity levels for the detection of h. pylori, compared with the commercial clo-test.