Comparison of diagnostic methods for detection of Helicobacter pylori

Of two hundred Ethiopian patients with dyspepsia, multiple biopsies were taken from the antrum of the stomach. Helicobacter pylori was cultured from 85% of duodenal ulcer and in 75% of chronic antral gastritis patients. The overall Helicobacter pylori positivity was 70%. The sensitivity, specificity, positive and negative predictive values of the tests as compared to culture were as follows, respectively: direct urease test 100%/87%/95%/100%, direct gram stain 60%/98%/99%/51%, histological gram stain 66%/97%/98%/56%, Giemsa stain 100%/97%/99%/100% and Gimenez stain 100%/87%/95%/100%. It is concluded that gram staining of direct tissue smear or histology is an insensitive method in the diagnosis of Helicobacter pylori. All the other tests, are shown to be valid. Urease test is an excellent test for provision of presumptive diagnosis of Helicobacter pylori while awaiting confirmation either by culture of histology.