Helicobacter pylori infection in childhood: H-pylori isolation rate in gastric juice in relation to positive serum antibody rates

We investigated the prevalence of Helicobacter pylori infection by isolation of H. pylori and by antibody detection in the serum of Japanese children. The children were distributed into four groups by age: group I, under 1 year; group II, 1-5 years; group III, 6-11 years; and group IV, 12-15 years. For the isolation of H. pylori, gastric juice was obtained from 15 children from middle class families. In the 103 samples obtained from asymptomatic children, H. pylori was not isolated in any from group I. The isolation rate in groups II, III, and IV was 3% (1/32), 20% (5/25), and 75% (3/4), respectively. In symptomatic children, H. pylori was isolated only in group I, II, III, and IV was 13% (6/47), 10% (11/112), 18% (16/89), and 26% (11/43), respectively, in asymptomatic children. In group I, however, 4 of 25 samples (18%) were obtained from babies under 3 months of age; this result was regarded as reflecting maternal antibodies. Nineteen samples were obtained from children with hepatitis A who lived in Nanki hospital for handicapped children, where hygiere was poor. The antibody positive rate in this population was 60% (3/5) in group III and 90% (9/10) in group IV. These results suggest that H. pylori infection in Japanese children is related to age and hygiene conditions. The antibody positive rate was similar to that reported in other countries.