DETERMINATION OF THE TEST-PERFORMANCE OF LESS COSTLY METHODS OF HELICOBACTER-PYLORI DETECTION

Since Helicobacter pylori (Hp) has become so important in the manageme nt of peptic ulcers, it is imperative that noninvasive and inexpensive methods of diagnosis be available. The objective of this prospective, double-blind study was to determine the performance of the noninvasiv e C-14-urea breath test and the less expensive hematoxylin-phloxin-saf fron (HPS) and Giemsa stains in the detection of this infection. As we ll, we set out to determine the minimal number of biopsies required to make an accurate diagnosis. Fifty consenting adults referred for gast roscopy underwent antral biopsies for HPS, Giemsa and Steiner silver s taining and a C-14-urea breath test. The ability of HPS, Giemsa, and t he breath test to differentiate between the presence or absence of Hp infection as defined by the silver stain was assessed using contingenc y table analysis. Hp was detected in 24 patients with the silver stain . Half of these patients had evidence of ulcer disease, compared to 3 of 26 patients who were negative for Hp on silver stain (p < 0.01). Th e Hp positive group were more: frequently male (62% vs. 31%,p < 0.05) and more often had chronic active gastritis (96% vs. 7.7%, p < 0.001). The sensitivity of the breath test, HPS, and Giemsa stains were 95.8% (95% confidence interval: 79-100%), 75% (53-90%), and 95.8% (79-100%) , respectively. Specificity was 100% (87-100%) for all 3 methods of de tection. The breath test was also able to discriminate between heavily infected and moderately infected patients as defined by silver stain (p < 0.05), and could be shortened from 30 to 15 min without any loss of accuracy. Two antral biopsies were sufficient to make an accurate d iagnosis. In conclusion, the C-14-urea breath test and Giemsa stain ha ve excellent test performance scores, and can be used with confidence in place of the expensive silver stain. Hematoxylin-phloxin-saffron (H PS) also has excellent specificity but is inadequate to rule out Hp in fection. Cost and discomfort could also be reduced by decreasing the n umber of antral biopsies to two, and by shortening the breath test fro m 30 to 15 min.