Evaluation of the string test for the detection of Helicobacter pylori

作     者：Rupert WL Leong Ching C Lee Thomas KW Ling WaiK Leung Joseph JY Sung 

作者机构：Department of GastroenterologyUniversity of New South WalesBankstown HospitalSydneyAustralia Department of Microbiology Chinese University of Hong KongPrince of Wales HospitalShatinHong KongChina Department of Medicine & TherapeuticsChinese University of Hong KongPrince of Wales HospitalShatinHone KongChina 

出 版 物：《World Journal of Gastroenterology》 (世界胃肠病学杂志（英文版）)

年 卷 期：2003年第9卷第2期

页      面：309-311页

核心收录：

学科分类：1002[医学-临床医学] 10[医学] 

基　　金：the Athelstan and Amy Saw Overseas Medical Research Fellowship from the University of Western Australia 

主　　题：幽门螺杆菌 活组织检查 消化道溃疡 细菌培养 内窥镜 无创性检查 

摘      要：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 Fasting patients swallowed the encapsulated-string(Entero-test Hp), which was withdrawn after 1 hour.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.