Epidemiology of Helicobacter pylori infection in Barbados

The epidemiology of Helicobacter pylori infection in Barbadian patients and controls was studied. H. pylori was isolated from biopsies from 50/100 (50%) adult patients undergoing endoscopy for investigation of upper gastrointestinal tract symptoms. Urease was detected in biopsies from 54 patients and gastritis was detected by histology in 71 patients. Serology was performed using a commercial ELISA method. Using an IgG concentration of 10 U/ml as a threshold, antibodies were detected in 78% of 100 patients undergoing endoscopy, 72% of 230 blood donors and 22% of 50 children. The mean antibody concentration was significantly higher in patients (92 U/ml) than in blood donors (49 U/ml) or in children (9.5 U/ml). Culture-positive patients (120 U/ml) had higher IgG concentrations than culture-negative patients (64 U/ml). Using isolation of H. pylori or a positive biopsy urease test as a measure of true prevalence of infection, the sensitivity of serology was 96%, the specificity 42%, positive predictive value 67% and negative predictive value 90%. Seroprevalence increased with age, to a peak of more than 90% in blood donors aged 50-59 years and in patients aged over 60 years. The epidemiology of H. pylori in Barbados is similar to that in developed countries, where few children are infected, but resembles other developing countries in the high seroprevalence observed in middle-aged adults. Our results confirm the utility of serology for detecting H. pylori by a non-invasive technique.