Survey of Hepatitis B Viral Markers at a Public Day School and a Residential Institution Sharing Mentally Handicapped Students

The prevalence of hepatitis B virus markers was studied among employees and clients at a nonresidential public school for the mentally handicapped and at a privately operated residential facility. In the residential institution, 73 (80%) of 91 clients and 15 (1601o) of 92 workers had positive tests for hepatitis B virus markers. Twenty-three clients, including six carriers of hepatitis B surface antigen (subtype ayw), received their education at the public school. Only two students (4%) who did not live at the residential institution and one employee (2%) had positive tests for hepatitis B virus markers. One of these students had acute hepatitis B infection, with hepatitis B surface antigen subtype ayw; the subtyping suggested that he had acquired the infection from one of the six carriers from the residential institution. Testing for IgM antibody to hepatitis B core antigen in single serum samples facilitated the identification of acute and chronic hepatitis B infection in children and staff of both facilities. The results show hepatitis B can be transmitted in this setting, and vaccination may be warranted for susceptible students and staff. Individuals living in residential institutions for the mentally retarded are at high risk for exposure to