Seroepidemiology of helicobacter pylori infection in Barbados - abstract

ABSTRACT

Helicobacter pylori is now recognised as the cause of chronic (type B) gastritis. We have previously reported on the detection of H.pylori in biopsies obtained by endoscopy of patients with upper gastrointestinal symptoms. An ELISA method was used to study the seroepidemiology of H.pylori infection in Barbadian patients and controls. Using an IgG concentration of 10 U/ml as a threshold, antibodies were detected in 78 percent of 100 patients undergoing endoscopy, 72 percent of 230 blood donors and 22 percent of 50 children. The mean antibody concentration was significantly higher in patients (91.9 U/ml) than in blood donors (48.56 U/ml) or in children (9.5 U/ml). Similarly, culture-positive patients (120 U/ml) had significantly higher IgG concentrations than in culture-negative patients (63.88 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 percent the specificity 42 percent, its positive predictive value was 67 percent and the negative predictive value was 90 percent. Seroprevalence increased with age, to a peak of more thatn 90 percent 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, in that few children are infected, but resembles other developing countries in the high seroprevalence observed in middle-aged adults. Our results confirm the utlitiy of serology for detecting H.pylori by a non-invasive technique (AU)