Evaluation of a newly developed office-based stool test for detecting Helicobacter pylori: an extensive pilot study

Several strategies have been used to detect Helicobacter pylori (Hp) infection along two lines: 1) direct detection of the bacteria, and 2) detection of antigen-antibody assay against Hp. The non-invasive methods include ELISA test of serum, salivary and urine, urea breath test, and detection of Hp antigen in stool. The latter method (HpSA) has been proven reliable and better than the ELISA test, for it can detect current Hp infection and is suitable for post-treatment follow-up. Now, a new commercial kit, ImmunoCard STAT HpSA (Meridian Bioscience Europe) has been developed to detect stool Hp antigen. It is simpler and less time-consuming than HpSA. The aim was to examine whether ImmunoCard STAT HpSA is qualified for diagnosis of Hp infection.

253 patients (163 men, 90 women, mean age: 53.3 +/- 13.9 y/o, range: 19-89 y/o) were enrolled in this study. All of them had undergone gastroendoscopy and urea breath test. 207 patients were diagnosed with peptic ulcer and 46 with gastritis. Stool samples were collected within 3 days of their visit for gastroendoscopy and were sent for the Immunocard test.

118 patients were diagnosed with Hp infection and of these, 113 were interpreted as positive by means of the Immunocard test. Among the other 135 patients without Hp infections, 123 were interpreted as negative by means of the Immunocard test. Sensitivity and specificity were 95.8% and 91.1%, and positive and negative predictive values were 90.4% and 96.1%.

The ImmunoCard STAT HpSA had high sensitivity, and specificity and could be used for mass screening. We concluded that it is a rapid, simple, cheap, reliable, and non-invasive strategy to detect current Hp infection and can be used in post-Hp eradication follow-up in Taiwan.