Prevalence of hepatitis B infection in long-stay mentally handicapped adults

The objective was to determine the prevalence of hepatitis B virus (HBV) in fection in long-stay institutionalized mentally handicapped adults and to d evelop a vaccination programme for them. The study was carried out in 1994. The subjects were 171 mentally handicapped adults aged 37-76 (median age 5 6) with a median hospital stay of 30 years (range 6-47). Markers for infect ion were determined using ELISA. Seronegative patients were vaccinated usin g the standard schedule, and the titre of antiHBs reached was determined la ter. The prevalence of seropositive subjects was 81.3%. Seropositive subjec ts had a longer hospital stay (median stay of 32 years, range: 15-47) than seronegative ones (median stay of 15 years, range: 6-33). A total of 43.3% of the vaccinated subjects developed antiHBs antibodies (GMT: 135 IU/l). Th e high prevalence of HBV exposure is probably a legacy of a past era which is reflected in patients with prolonged institutionalisation in a closed re gime. The need for immediate vaccination of mentally handicapped subjects i s of the utmost importance, as it has been shown that the response to the v accine worsens with age.