CAJ | 학술논문

AIM: Helicobacter pylori can be diagnosed by invasive ornon-invasive tests but to obtain bacteria for culture andantibiotic susceptibility testing, an upper GI endoscopy isoften required. The string test may be a minimally-invasivealternative method of obtaining H. pylori samples. This studyevaluates the sensitivity and specificity of the string test inthe diagnosis of H. pylori in comparison with endoscopicmeans of diagnosis.METHODS: This was a prospective open comparative studyof patients with dyspepsia with endoscopy-based tests asgold standard (defined as a positive CLO test and antralhistology). Fasting patients swallowed the encapsulated-string(Entero-test Hp), which was withdrawn after 1 hour. Thegastric juice from the string was plated onto H. pylori-selectivemedia for culture. Helicobacter pylori was identified by typicalcolony morphology, gram stain and biochemical test results.RESULTS: Thirty dyspeptic patients were recruited of whom21 (70 %) were positive for H. pylori according to the goldstandard. The sensitivity, specificity, positive predictive value,and negative predictive value for the string test were 38 %,100 %, 100 % and 41% respectively, and for endoscopicbiopsies 81%, 100 %, 100 %, 69 % respectively (P=0.004).Logistic regression showed that only abundant growthdensity from endoscopic biopsy cultures to be a predictor ofa positive string test (P=0.018).CONCLUSION: The string test is an alternative method toendoscopy in obtaining H. pylori but has a low sensitivitycompared to endoscopic biopsies.