Risk factors for hepatitis B at a residential institution for intellectually handicapped persons.

We conducted a cross sectional study to evaluate risk factors for hepatitis B (HBV) infection among residents and staff at Braemar Hospital in Nelson. We obtained serum and abstracted medical charts for 114 of the 122 (93%) residents; 129 of 226 (57%) staff members completed questionnaires and provided serum. Seventy (61%) of the residents had serological markers of past HBV infection, including 42 (37%) who were identified as carriers. Residents' risk of being infected increased by 17% for each additional year they had lived in this institution; there were no significant differences in the likelihood of having markers of HBV infection by a person's age at first admission, sex, ethnicity, admission diagnosis, medical history, or various behavioural attributes. Among staff, 20 (16%) showed evidence of past exposure to HBV, but none were identified as being carriers; of these, 5 (25%) reported having received hepatitis B vaccine. Excluding the vaccinated persons who were seropositive, there were no demographic or occupational risk factors that were significantly associated with having serological markers of past HBV exposure. To control further HBV transmission in this setting, all current and future residents, as well as staff members who have direct contact with residents, should be screened for serological markers of HBV and persons identified as being susceptible should be vaccinated.