Hepatitis B and workers in institutions for the mentally retarded: risk of infection for staff in patient care.

In the fall of 1982, we conducted a serosurvey of 920 of 933 employees in a large residential institution for the mentally retarded in Salem, Oregon. This survey demonstrated an overall prevalence of 10% for antibody to hepatitis B core antigen (anti-HBc), a marker of present or previous hepatitis B virus infection. Antibody positivity was significantly associated with a history of ever having worked in a position involving direct patient care (adjusted odds ratio = 3.1, 95% confidence interval 2.6-4.2). The length of time employed at the institution was significantly associated with an increasing prevalence of anti-HBc positivity among those persons who had ever worked in direct patient care (chi 2 for linear trend = 19.3, P less than .00001, one tail), but not among those employees who had never worked in patient contact. This evidence supports the Immunization Practices Advisory Committee (ACIP) recommendation of hepatitis B virus screening and, where appropriate, vaccinations for those workers in institutions for the mentally retarded who work closely with patients.