Abstract
Serial tests for the HB antigen were carried out in an institution for the mentally retarded. During the study the frequency of the antigen carrier was found to be 23%, of which one third had a persistent antigenemia. The antigenemia was found more frequently in the younger (under 10 years of age) than in the older. In contrast, the incidence of the antibody carrier was higher in the older. The antigen was acquired in 2 newly admitted patients 3 and 4 months after institutionalization. The HB antigen was detected by means of RIA in saliva obtained from 5 patients who were positive for the antigen in serum. The salivary antigen may be an important source for spreading the antigen in a closed environment.
